Eleven: Fix hidden shuffle and repeat in some densities

Prior to this change, devices like Fairphone 4 with a density of 440
do not show the shuffle or repeat buttons.

Test: Manual: `adb shell wm density 440`, observe the playback screen
controls for presence of shuffle and repeat buttons.

Change-Id: I8341099efceb3799602ee6d68ebb569efe4ffc88
diff --git a/res/layout/main_playback_controls.xml b/res/layout/main_playback_controls.xml
index d58a367..27863fa 100644
--- a/res/layout/main_playback_controls.xml
+++ b/res/layout/main_playback_controls.xml
@@ -74,7 +74,7 @@
         android:id="@+id/action_button_shuffle"
         android:layout_width="@dimen/audio_player_controls_end_button_width"
         android:layout_height="@dimen/audio_player_controls_end_button_height"
-        android:layout_margin="@dimen/audio_player_controls_end_button_margin"
+        android:layout_marginEnd="@dimen/audio_player_controls_end_button_margin"
         android:contentDescription="@string/accessibility_shuffle"
         android:foreground="?android:selectableItemBackgroundBorderless"
         android:scaleType="fitCenter"
@@ -87,7 +87,7 @@
         android:id="@+id/action_button_previous"
         android:layout_width="@dimen/audio_player_controls_end_button_width"
         android:layout_height="@dimen/audio_player_controls_end_button_height"
-        android:layout_margin="@dimen/audio_player_controls_end_button_margin"
+        android:layout_marginEnd="@dimen/audio_player_controls_end_button_margin"
         android:foreground="?android:selectableItemBackgroundBorderless"
         android:scaleType="fitCenter"
         android:src="@drawable/btn_playback_previous"
@@ -111,7 +111,7 @@
         android:id="@+id/action_button_next"
         android:layout_width="@dimen/audio_player_controls_end_button_width"
         android:layout_height="@dimen/audio_player_controls_end_button_height"
-        android:layout_margin="@dimen/audio_player_controls_end_button_margin"
+        android:layout_marginStart="@dimen/audio_player_controls_end_button_margin"
         android:foreground="?android:selectableItemBackgroundBorderless"
         android:scaleType="fitCenter"
         android:src="@drawable/btn_playback_next"
@@ -123,7 +123,7 @@
         android:id="@+id/action_button_repeat"
         android:layout_width="@dimen/audio_player_controls_end_button_width"
         android:layout_height="@dimen/audio_player_controls_end_button_height"
-        android:layout_margin="@dimen/audio_player_controls_end_button_margin"
+        android:layout_marginStart="@dimen/audio_player_controls_end_button_margin"
         android:contentDescription="@string/accessibility_repeat"
         android:focusable="true"
         android:foreground="?android:selectableItemBackgroundBorderless"