title: Not getting email from facebook after logging success, it is giving name only
body: <pre><code>callbackManager = CallbackManager.Factory.create();  
  fbLoginButton.setReadPermissions("email");
          fbLoginButton.registerCallback(callbackManager, new FacebookCallback&lt;LoginResult&gt;() {
              @Override
              public void onSuccess(LoginResult loginResult) {
  
              GraphRequestAsyncTask request = GraphRequest.newMeRequest(loginResult.getAccessToken(),
                      new GraphRequest.GraphJSONObjectCallback() {
                          @Override
                          public void onCompleted(JSONObject object, GraphResponse response) {
  
                              Toast.makeText(getApplicationContext(), "Data" + object.toString(), Toast.LENGTH_LONG).show();
  
                              etEmail.setText(object.optString("email"));
                              etName.setText(object.optString("name"));
  
  
                          }
                      }).executeAsync();
  
          }
  
          @Override
          public void onCancel() {
  
          }
  
          @Override
          public void onError(FacebookException error) {
  
          }
      });
  
  
      buttonFbSignup.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              fbLoginButton.performClick();
          }
      });
  </code></pre>