Fix order of playback controls in RTL layout

Issue: androidx/media#227

#minor-release

PiperOrigin-RevId: 497159283
(cherry picked from commit 80603427ab)

RELEASENOTES.md

@@ -30,6 +30,9 @@
         `PlayerView.setControllerVisibilityListener(PlayerControlView.VisibilityListener)`
         to ensure visibility changes are passed to the registered listener
         ([#229](https://github.com/androidx/media/issues/229)).
+    *   Fix the ordering of the center player controls in `PlayerView` when
+        using a right-to-left (RTL) layout
+        ([#227](https://github.com/androidx/media/issues/227)).
 *   Session:
     *   Add abstract `SimpleBasePlayer` to help implement the `Player` interface
         for custom players.

libraries/ui/src/main/res/layout/exo_player_control_view.xml

@@ -131,7 +131,8 @@
       android:background="@android:color/transparent"
       android:gravity="center"
       android:padding="@dimen/exo_styled_controls_padding"
-      android:clipToPadding="false">
+      android:clipToPadding="false"
+      android:layoutDirection="ltr">
 
     <ImageButton android:id="@id/exo_prev"
         style="@style/ExoStyledControls.Button.Center.Previous"/>