Create new icons UI floating tabs

Incremental CL to create the new icons UI. Made sure UI responds well to
scenarios where either style or shape, or both, are not available.

Flag: com.android.systemui.shared.extendible_theme_manager
Bug: 397782741
Test: manually verified with flag on and off
Test: manually verified with scenarios of style or shape not available
Change-Id: Iaf14aae6a6009a5e76322f6774a3fa504b7494c4