Fix bounds calculation in TV PipController

Use PipBoundsState in .tv.PipController for tracking Pip window bounds,
instead of tracking them "internally".
Fix a bug, where Pip window receives a wrong aspect ratio after Pip menu
closes if a custon aspect ration is specified.

Bug: 174646148
Bug: 168447740
Test: atest WMShellFlickerTests:TvPipBasicTest
Test: atest WMShellFlickerTests:TvPipMenuTests
Change-Id: I5e609d5c22591d6eb523ef08118a4aa11a220326