Clean up the logic around starting the linking flow (#377)

Author: amandle

auth/src/main/java/com/firebase/ui/auth/ui/AcquireEmailHelper.java

@@ -17,6 +17,7 @@
 import android.content.Intent;
 import android.support.annotation.NonNull;
 
+import android.util.Log;
 import com.firebase.ui.auth.R;
 import com.firebase.ui.auth.ui.account_link.WelcomeBackIdpPrompt;
 import com.firebase.ui.auth.ui.email.RegisterEmailActivity;
@@ -80,30 +81,22 @@ private void startEmailHandler(String email, List<String> providers) {
             mActivityHelper.startActivityForResult(registerIntent, RC_REGISTER_ACCOUNT);
         } else {
             // account does exist
-            for (String provider : providers) {
-                if (provider.equalsIgnoreCase(EmailAuthProvider.PROVIDER_ID)) {
-                    Intent signInIntent = SignInActivity.createIntent(
-                            mActivityHelper.getApplicationContext(),
-                            mActivityHelper.getFlowParams(),
-                            email);
-                    mActivityHelper.startActivityForResult(signInIntent, RC_SIGN_IN);
-                    return;
-                }
-
-                Intent intent = WelcomeBackIdpPrompt.createIntent(
+            String provider = providers.get(0);
+            if (provider.equalsIgnoreCase(EmailAuthProvider.PROVIDER_ID)) {
+                Intent signInIntent = SignInActivity.createIntent(
                         mActivityHelper.getApplicationContext(),
                         mActivityHelper.getFlowParams(),
-                        provider,
-                        null,
                         email);
+                mActivityHelper.startActivityForResult(signInIntent, RC_SIGN_IN);
+            } else {
+                Intent intent = WelcomeBackIdpPrompt.createIntent(
+                    mActivityHelper.getApplicationContext(),
+                    mActivityHelper.getFlowParams(),
+                    provider,
+                    null,
+                    email);
                 mActivityHelper.startActivityForResult(intent, RC_WELCOME_BACK_IDP);
-                return;
             }
-
-            Intent signInIntent = new Intent(
-                    mActivityHelper.getApplicationContext(), SignInActivity.class);
-            signInIntent.putExtra(ExtraConstants.EXTRA_EMAIL, email);
-            mActivityHelper.startActivityForResult(signInIntent, RC_SIGN_IN);
         }
     }