Make libhidl_gtest_helper vendor_available.

This is needed for vts tests to be marked as vendor tests. Vendor vts
tests are useful when we're testing framework hals.

Bug: 231517902

Test: build vendor VtsHalCameraProviderV2_4TargetTest

Change-Id: I5abab3c29f2212a0680fd179462ff4c254afe1b9
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
1 file changed