Cleanup `OverrideMinAspectRatio` CTS tests

Remove unecesary enable/disableCompatChanges annotations
Add ApiTest and RequireFlagEnabled annotations
Add Javadoc and comments for each test

Fixes: 319256120
Test: atest CtsWindowManagerDeviceDisplay:CompatChangeTests
Change-Id: I64a5e816056ea453669f28235a1cc98c77877e9e
1 file changed