Fix TaskFragmentTrustedModeTest

The condition was inverted, and led to #reparentChildren didn't work.
This CL also removes some minimum dimension checks because it is covered in TaskFragment#isAllowedToEmbedActivity(ActivityRecord).


Test: atest TaskFragmentTrustedModeTest TaskFragmentOrganizerTest
Test: atest TaskFragmentOrganizerPolicyTest SplitActivityLifecycleTest
Fixes: 238054859
Bug: 233578672

Merged-In: Ic58edee8e239e94b9986f06b499281487a9a973d
Change-Id: Ic58edee8e239e94b9986f06b499281487a9a973d