Run VTS HWC tests on the AIDL repo itself.

As VTS for HWC is now on drm_hwc's presubmit, it's crucial that it
doesn't fail in presubmit due to any changes within this directory, as
this will block drm_hwc gerrit due to failures elsewhere, so it's
prudent to run these tests in presubmit.

Bug: b/383125262, b/352791537
Test: N/A
Flag: TEST_ONLY
Change-Id: I8b05065e7e88a32a75808b62005657296d4d616e