[6/n] Define AppCompatOrientationPolicy and related capability class

We extract the app compat logic related of orientation override
from LetterboxUiController and encasulate it into a new
AppCompatOrientationPolicy along with a specific capability
class named AppCompatOrientationCapability.

Flag: EXEMPT refactor
Bug: 346264992
Test: atest WmTests:LetterboxUiControllerTest
Test: atest WmTests:SizeCompatTests

Change-Id: I022608400a745149d93243a2a0e1d9a618ea782f