Clean up playback controls xml a little

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140374149

library/src/main/res/layout/exo_playback_control_view.xml

@@ -51,17 +51,18 @@
   <LinearLayout
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:layout_marginTop="4dp"
+    android:gravity="center_vertical"
     android:orientation="horizontal">
 
     <TextView android:id="@id/exo_position"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
-      android:layout_gravity="center_horizontal"
       android:textSize="14sp"
       android:textStyle="bold"
-      android:paddingTop="4dp"
-      android:paddingStart="4dp"
-      android:paddingEnd="4dp"
+      android:paddingLeft="4dp"
+      android:paddingRight="4dp"
+      android:includeFontPadding="false"
       android:textColor="#FFBEBEBE"/>
 
     <SeekBar android:id="@id/exo_progress"
@@ -73,12 +74,11 @@
     <TextView android:id="@id/exo_duration"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
-      android:layout_gravity="center_horizontal"
       android:textSize="14sp"
       android:textStyle="bold"
-      android:paddingTop="4dp"
-      android:paddingEnd="4dp"
-      android:paddingStart="4dp"
+      android:paddingLeft="4dp"
+      android:paddingRight="4dp"
+      android:includeFontPadding="false"
       android:textColor="#FFBEBEBE"/>
 
   </LinearLayout>