¿Cómo redirigir a un usuario a una actividad específica en Cloud Firestore?

Mientras registraba una cuenta usando la autenticación de Firebase, almacené correos electrónicos en 2 categorías Profesor y Estudiante. Agrego correos electrónicos a Firestore 2 categorías diferentes Profesor y Estudiante con email y password. Cuando inicio sesión, quiero verificar que el correo electrónico pertenece a qué categoría (Profesor o Estudiante) ¿cómo puedo hacer eso? Probé la consulta de firestore isequalsto pero no diferenció.

Aquí está mi base de datos

Profesor

Estudiante

¿Alguna otra solución posible?

aquí está mi código para la actividad de inicio de sesión

package com.example.dell.step;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.QuerySnapshot;

public class LoginActivity extends AppCompatActivity {


    private Button mRegbtn;
    private Button mloginbtn;
    private EditText mEmail;
    private EditText mPassword;

    private Toolbar mToolbar;

    private FirebaseAuth mAuth;

    private ProgressDialog mLoginDialog;
    private FirebaseFirestore firebaseFirestore;
    private CollectionReference collectionReference_I;
    private CollectionReference collectionReference_S;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);


        mAuth = FirebaseAuth.getInstance();

        //Progress Dialog

        mLoginDialog = new ProgressDialog(this);

        //FOr Toolbar

        mToolbar = findViewById(R.id.login_toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setTitle("Login Account");


        mloginbtn = findViewById(R.id.login_btn);
        mEmail = findViewById(R.id.login_email);
        mPassword = findViewById(R.id.login_password);

        mRegbtn = findViewById(R.id.login_reg_btn);

        firebaseFirestore = FirebaseFirestore.getInstance();

        mRegbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent regIntent = new Intent(LoginActivity.this, RegisterActivity.class);
                startActivity(regIntent);
                finish();

            }
        });


        mloginbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String email = mEmail.getText().toString();
                String password = mPassword.getText().toString();

                if (!TextUtils.isEmpty(email) && !TextUtils.isEmpty(password)) {
                    mLoginDialog.setTitle("Login User");
                    mLoginDialog.setMessage("Please wait while we login to your account :)");
                    //it stops cancel Dialog when user touch on screen
                    mLoginDialog.setCanceledOnTouchOutside(false);
                    mLoginDialog.show();

                    login_user(email, password);
                }
            }
        });


    }

    private void login_user(final String email, final String password) {

        collectionReference_I = firebaseFirestore.collection("Teacher");
        collectionReference_S = firebaseFirestore.collection("Student");

        collectionReference_I.whereEqualTo("teacher_email", email).get().addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
            @Override
            public void onSuccess(QuerySnapshot documentSnapshots) {

                mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {


                        if (task.isSuccessful()) {

                            //Dismiss the progress Dialog
                            mLoginDialog.dismiss();


                            //user is registered
                            Toast.makeText(LoginActivity.this, "Welcome to Teacher Account", Toast.LENGTH_SHORT).show();
                            Intent mainIntent = new Intent(LoginActivity.this, MainActivity.class);
                            startActivity(mainIntent);
                            finish();


                        } else {

                            mLoginDialog.hide();

                            //if user is not registered
                            Toast.makeText(LoginActivity.this, "Cannot Log in Please check the form and try again!", Toast.LENGTH_LONG).show();

                        }

                    }
                });


            }
        });

        collectionReference_S.whereEqualTo("Student_email", email).get().addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
            @Override
            public void onSuccess(QuerySnapshot documentSnapshots) {

                mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {


                        if (task.isSuccessful()) {

                            //Dismiss the progress Dialog
                            mLoginDialog.dismiss();


                            //user is registered
                            Toast.makeText(LoginActivity.this, "Welcome to Student Account", Toast.LENGTH_SHORT).show();
                            Intent mainIntent = new Intent(LoginActivity.this, StudentMain.class);
                            startActivity(mainIntent);
                            finish();


                        } else {

                            mLoginDialog.hide();

                            //if user is not registered
                            Toast.makeText(LoginActivity.this, "Cannot Log in Please check the form and try again!", Toast.LENGTH_LONG).show();

                        }

                    }
                });


            }
        });


    }
}