Initialize Firebase and set up Google Auth Provider.
```javascript
import { initializeApp } from "firebase/app";
import { getAuth, signInWithPopup, GoogleAuthProvider } from "firebase/auth";

const firebaseConfig = { /_ your firebase config _/ };
const app = initializeApp(firebaseConfig);
const auth = getAuth(app);
const provider = new GoogleAuthProvider();

const signInWithGoogle = () => {
signInWithPopup(auth, provider)
.then((result) => {
const user = result.user;
console.log(user);
})
.catch((error) => {
console.error(error);
});
};
```

Initialize Firebase and set up Facebook Auth Provider.
```java
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

// Initialize Facebook SDK and Firebase Auth
CallbackManager callbackManager = CallbackManager.Factory.create();
FirebaseAuth mAuth = FirebaseAuth.getInstance();

LoginButton loginButton = findViewById(R.id.login_button);
loginButton.setPermissions("email", "public_profile");
loginButton.registerCallback(callbackManager, new FacebookCallback() {
@Override
public void onSuccess(LoginResult loginResult) {
handleFacebookAccessToken(loginResult.getAccessToken());
}

@Override
public void onCancel() {
// Handle cancellations
}

@Override
public void onError(FacebookException exception) {
// Handle errors
}
});

private void handleFacebookAccessToken(AccessToken token) {
AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
mAuth.signInWithCredential(credential)
.addOnCompleteListener(this, (task) -> {
if (task.isSuccessful()) {
FirebaseUser user = mAuth.getCurrentUser();
// Navigate to next activity or update UI
} else {
// Handle failure
}
});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
}
```