Fix Letterboxing for Transparent Activities

We want a not resizable transparent activity to inherits
the constraints from the activity below. This allows the
transparent activity to be letterboxed.
The specific logic for transparent activities is enabled
when the config_letterboxIsEnabledForTranslucentActivities
flag is true.

Fixes: 220703089
Test: Run `atest SizeCompatTests` with the following tests:
  testApplyStrategyToTranslucentActivities
  testTranslucentActivitiesDontGoInSizeCompactMode
  testNotApplyStrategyToTranslucentActivitiesWithDifferentUid
  testApplyStrategyToMultipleTranslucentActivities

Change-Id: I6b5e8517ae8286f7543c3f57c158276aab6cfbfc