Inject AppCompatConfiguration to WindowManager

AppCompatConfiguration reads real values from the device, and tries to
access actual files during startup and when settings change. This works
for instrumentation tests but should be avoided when writing unit tests.

Flag: EXEMPT mechanical refactor
Test: atest WmTests
Bug: 362981229
Change-Id: I493eb9e0cc111c69556c7589d905cdc43abb588d