Show volume dialog vertically in all rotations

The volume dialog will be volume_dialog_base_margin dp away from
the nearest thing on its right, be that nav bar, cutout, or the
side of the device.

Additionally made the dialog a bit shorter and skinnier to fit.

Test: manual, used dialog in all rotations in rtl and ltr
Change-Id: Ia2642ede7670989dcc2b7612cc8c3bf2ba94fbc7
Fixes: 72711737