Create separate source of truth for display info

Create a separate class keeping track of display related
info, such as display layout, bounds and id. Make sure
its internal state gets updated as needed and other classes
such as PipSizeSpecHandler and PipBoundsState use it instead
of subscribing to display changes themselves.

Bug: 268390405

Test: atest WMShellUnitTests
Change-Id: I633ab09faa1ae3b5103078155e3781f3433ad1fc
Merged-In: I633ab09faa1ae3b5103078155e3781f3433ad1fc