Use @EnableFlags and @DisableFlags annotations instead of soon-to-be deprecated methods.

These tests are build with -Werror, so we need to migrate them.

Bug: 341129262
Change-Id: I0bd8d03f16f0fef1772826a24f663a7babe2bfcd
Flag: test_only
Test: presubmit
Merged-In: I7661dd73c3f9d0e44cabd928b96cf2affc9cae22