title: OnCreateOptionsMenu doesn't get called on Android 7.0
body: <p>As in the title mentioned the <strong>OnCreateOptionsMenu</strong> method doesn't get called after I updated my system to Android 7.0.</p>
  
  <p>Before the update I used <em>Android 6.0</em> and it worked without any issues.
  If I test it on my other phone with 6.0 it is still working (same code). </p>
  
  <p>Is there any problem with this method on Android 7.0 or is something wrong in my code?</p>
  
  <p>The part of my MainActivity.cs where I set the <a href="https://developer.xamarin.com/guides/android/user_interface/toolbar/part-1-replacing-the-action-bar/" rel="nofollow noreferrer">toolbar</a></p>
  
  <pre><code>[Activity(Label = "App", Icon = "@drawable/icon", MainLauncher = true, Theme = "@style/Theme.AppCompat.Light.NoActionBar",ScreenOrientation = Android.Content.PM.ScreenOrientation.Portrait)]
  public class MainActivity : AppCompatActivity
  {
      protected override void OnCreate(Bundle bundle)
      {
           base.OnCreate(bundle);
           SetContentView(Resource.Layout.Main);
  
           var toolbar = FindViewById&lt;Android.Widget.Toolbar&gt;(Resource.Id.toolbar);
           toolbar.SetTitleTextColor(Color.White);
           SetActionBar(toolbar);
      }
  
      public override bool OnCreateOptionsMenu(IMenu menu)
      {
          MenuInflater.Inflate(Resource.Menu.top_menu_start, menu);
          return base.OnCreateOptionsMenu(menu);
      }
  }
  </code></pre>
  
  <p><strong>Main.axml</strong></p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
      &lt;Toolbar
          android:id="@+id/toolbar"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:background="#1D1D1D"
          android:theme="@android:style/ThemeOverlay.Material.Dark.ActionBar" /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p><strong>top_menu_start</strong></p>
  
  <pre><code>&lt;menu xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;item
         android:id="@+id/start_listview"
         android:icon="@drawable/icon_posts_list"
         android:showAsAction="ifRoom"
         android:title="startListview" /&gt;
    &lt;item
         android:id="@+id/start_pager"
         android:icon="@drawable/icon_posts_kacheln"
         android:showAsAction="ifRoom"
         android:title="startPager" /&gt;
    &lt;item
         android:id="@+id/doSomething"
         android:icon="@drawable/icon"
         android:showAsAction="ifRoom"
         android:title="doSomething" /&gt;
  &lt;/menu&gt;
  </code></pre>