title: BottomNavigationView on databinding inside viewmodel
body: <p>layout:</p>
  
  <pre><code>&lt;android.support.design.widget.BottomNavigationView
                  android:id="@+id/navigation"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_gravity="bottom"
               app:onNavigationItemSelected="@{viewModel.onNavigationItemSelected}"
                  android:background="?android:attr/windowBackground"
                  app:menu="@menu/menu_home_tab" /&gt;
  </code></pre>
  
  <p>code:</p>
  
  <pre><code>@BindingAdapter("onNavigationItemSelected")
      public static void setOnNavigationItemSelected(
              BottomNavigationView view, BottomNavigationView listener) {
          view.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
              @Override
              public boolean onNavigationItemSelected(@NonNull MenuItem item) {
  
                  switch (item.getItemId()) {
                      case R.id.navigation_dashboard:
                          Log.d("test","test1");
                          return true;
                      case R.id.navigation_notifications:
                          Log.d("test","test2");
                          return true;
  
                  }
                  return false;
              }
  
          });
  
      }
  </code></pre>
  
  <p>This returns an error</p>
  
  <pre><code>Error:(183, 49) Could not find accessor viewmodel.onNavigationItemSelected 
  </code></pre>
  
  <p>I am trying to implement databinding on my bottomnavigationview</p>