Adds unit tests for PipBoundsHandler

Per go/pip-cts-strategy, PiP bounds such as the default and movement
ones are not CDD related, neither the save/restore of PiP location.

These tests are now migrated to SysUI component.

Bug: 141200935
Test: atest PipBoundsHandlerTest
Change-Id: I379252c1713a3763bf0c784b14340e18612d9861