Use position in window for volume touchable insets.

For a currently unknown reason (this bug began yesterday, but volume files have not changed in over a week), the touchable insets are shifted ~550px to the left, which means you can't interact with the volume panel.

Bug: 184485868
Test: manual
Change-Id: I88674a64f1f686c1f09e737bf623de7875e799c1