Relaxing FGSes under prototype_aggressive_freezing

This is needed to rollout the flag to more devices so we can find and
fix any other problems.

Flag: com.android.server.am.prototype_aggressive_freezing

Test: atest FrameworksMockingServicesTests:MockingOomAdjusterTests

Bug: 370798593
Change-Id: Ib435944dd7164018a2c1a69c18f5bc7d952243e0