Add volume dialog background animation

This CL applies animation on volume dialog background view when ringer
drawer expands and collapses. It also applies spring animation on the
background view when ringer buttons are selected.

Flag: com.android.systemui.volume_redesign
Bug: 369995871
Test: Checked UI.
Change-Id: I1fdadfb34c7383f239cd40f2b8b495487e53925f