Force LTR layout in this view because the "playback" button should not be mirrored in RTL.

In this specific case, the drawable (triangle_right) used in this view
is _not_ autoMirrored which is correct. But the `layout_marginStart`
attribute adds the margin to the wrong side of the view that breaks the
appearance.

c.f. https://material.io/design/usability/bidirectionality.html#mirroring-elements

app/src/main/res/layout/mediapicker_media_item.xml

@@ -34,6 +34,7 @@
             android:layout_marginStart="2dp"
             android:tint="@color/core_ultramarine"
             android:scaleType="fitXY"
+            android:layoutDirection="ltr"
             app:srcCompat="@drawable/triangle_right" />
 
     </FrameLayout>