Update Volume Panel sliders to match the updated design

This change makes sure the VolumeDialogSliderTrack supports rtl and is
suitable for horizontal sliders

Flag: com.android.systemui.volume_redesign
Fixes: 399342224
Test: manual on foldable. Open Volume Panel and observe the sliders
Test: atest VolumePanelScreenshotTest
Test: atest VolumeDialogScreenshotTest
Change-Id: I43480d6c28cb9c63a2f3d508a53141f44251ad68