Rework footer animation transition

The new animation fades the whole footer when the components set
changes. Compose doesn't animate size of the weighted children which
caused the previous animation to be jittery

Flag: com.android.systemui.new_volume_panel
Bug: 343351939
Test: atest VolumePanelScreenshotTest
Test: manual on the phone with ANC enabled headset.
Change-Id: Ic74bb406f086652ecc3bf0ca172e39229ba0aaed