title: The shadow of ImageButton with transparent background
body: <p>I have an ImageButton. When I'd added transparent background, the shadow losed. How to fix it without third-party libraries?</p>
  
  <pre><code>                &lt;ImageButton
                  android:id="@+id/player_activity_previous_button"
                  android:background="@android:color/transparent"
                  android:tint="@color/color_for_buttons"
                  android:src="@drawable/ic_skip_previous_48"
                  android:layout_width="64dp"
                  android:layout_height="64dp"
                  android:layout_toLeftOf="@id/player_activity_play_pause_button"
                  android:layout_centerVertical="true"
                  android:stateListAnimator="@null"
                  android:elevation="4dp"
                  android:translationZ="4dp"/&gt;
  </code></pre>