update tests to account for the display area

Screenshots bitmap is for the entire physical display. With multiple TDA its possible that application is not running on fullscreen. Tests should account for the bounds of the display area within which the activity is running.

Bug: 228639659
Fix: 227422236
Test: atest AssistTestBase
Change-Id: Ifc47c99942da534137abbd48520dbab5cf2f91d0
(cherry picked from commit 02912c6f74a2b4dacde1308ffb8d65baa155cdd4)
3 files changed