Fix getContext NPE in saveCredentialsOrFinish

Author: SUPERCILEX

auth/src/main/java/com/firebase/ui/auth/util/signincontainer/SaveSmartLock.java

@@ -15,6 +15,7 @@
 package com.firebase.ui.auth.util.signincontainer;
 
 import android.app.PendingIntent;
+import android.content.Context;
 import android.content.Intent;
 import android.content.IntentSender;
 import android.net.Uri;
@@ -49,6 +50,8 @@ public class SaveSmartLock extends SmartLockBase<Status> {
     private static final int RC_SAVE = 100;
     private static final int RC_UPDATE_SERVICE = 28;
 
+    private Context mAppContext;
+
     private String mName;
     private String mEmail;
     private String mPassword;
@@ -77,6 +80,12 @@ public static SaveSmartLock getInstance(FragmentActivity activity, FlowParameter
         return result;
     }
 
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        mAppContext = context.getApplicationContext();
+    }
+
     @Override
     public void onConnected(Bundle bundle) {
         if (TextUtils.isEmpty(mEmail)) {
@@ -205,7 +214,7 @@ public void saveCredentialsOrFinish(FirebaseUser firebaseUser,
         mProfilePictureUri = firebaseUser.getPhotoUrl() != null ? firebaseUser.getPhotoUrl()
                 .toString() : null;
 
-        mGoogleApiClient = new Builder(getContext().getApplicationContext())
+        mGoogleApiClient = new Builder(mAppContext)
                 .addConnectionCallbacks(this)
                 .addOnConnectionFailedListener(this)
                 .addApi(Auth.CREDENTIALS_API)