Fix text alignment in RTL mode for volume sliders

The volume bars with layout preference_volume_slider won't align title text right in RTL mode (Force RTL layout direction is Developer options),
e.g. Sound & vibration page, Audio sharing page.

Test: manual
Bug: 359514080
Flag: EXEMPT minor layout change
Change-Id: I43daa46438e3fa0a879d831a97d05b31c7dcb52f

res/layout/preference_volume_slider.xml

@@ -42,6 +42,7 @@
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:singleLine="true"
+                android:textAlignment="viewStart"
                 android:textAppearance="?android:attr/textAppearanceListItem"
                 android:ellipsize="marquee"
                 android:fadingEdge="horizontal"/>