Enable EnforcePermission linters for test sources

Increase the scope of the linters to be executed even for tests.

Bug: 270596429
Test: m lint-check
Test: remove annotation and helper call in EnforcePermissionTestHelper;
      m lint-check; the two errors are raised.
Change-Id: Ic8348b668664747b8a1f3c56359cdf9c02132f59