title: Android - Overflow Menu and Back Button not showing in Collapsing Toolbar
body: <p>I'm trying to implement features from the new Design Support Library to create a parallax scrolling toolbar which looks similar to the new material design WhatsApp profile pages. However, I can't get the overflow menu and back button to show in the top corners.</p>
  
  <p>I have tried using the following methods to display the back button, but none of them works.</p>
  
  <pre><code>    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
      getSupportActionBar().setHomeButtonEnabled(true);
      getSupportActionBar().setDisplayShowHomeEnabled(true);
  </code></pre>
  
  <p>And overwriting the onCreateOptionsMenu method for the overflow menu also didn't work.</p>
  
  <p>Does anyone know how to add these toolbar icons to a CollapsingToolbar from the Design Support Library? Below is my layout xml for the activity. Thanks! </p>
  
  <pre><code>&lt;android.support.design.widget.CoordinatorLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/main_content"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:fitsSystemWindows="true"&gt;
  
  &lt;android.support.design.widget.AppBarLayout
      android:id="@+id/appbar"
      android:layout_width="match_parent"
      android:layout_height="256dp"
      android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
      android:fitsSystemWindows="true"&gt;
  
      &lt;android.support.design.widget.CollapsingToolbarLayout
          android:id="@+id/collapsing_toolbar"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:layout_scrollFlags="scroll|exitUntilCollapsed"
          android:fitsSystemWindows="true"
          app:contentScrim="@color/primary"
          app:expandedTitleMarginStart="48dp"
          app:expandedTitleMarginEnd="64dp"&gt;
  
          &lt;ImageView
              android:id="@+id/backdrop"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:src="@drawable/headerbg"
              android:scaleType="centerCrop"
              android:fitsSystemWindows="true"
              app:layout_collapseMode="parallax" /&gt;
  
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              app:popupTheme="@style/Theme.AppCompat.Light.DarkActionBar"
              app:layout_collapseMode="pin" /&gt;
  
      &lt;/android.support.design.widget.CollapsingToolbarLayout&gt;
  
  &lt;/android.support.design.widget.AppBarLayout&gt;
  
  &lt;android.support.v4.widget.NestedScrollView
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_gravity="fill_vertical"
      android:layout_marginBottom="?attr/actionBarSize"
      app:layout_behavior="@string/appbar_scrolling_view_behavior"&gt;
  
  &lt;/android.support.v4.widget.NestedScrollView&gt;
  </code></pre>
  
  <p></p>