Moving taskbar lifecycle to TouchInteractionService

> Inflating taskbar views with a non-launcher window context
> Removing separate taskbar view in Launcher
> Handling taskbar icon clicks directly instead of going via launcher
> Fixing some relayouts during show/hide animation

Bug: 187353581
Test: Manual
Change-Id: Ia7d44acbb770bf0345922234b3daa5cc040a5843