Explicitly unfreeze the Automotive HALs

Per discussion with Treble team, keeping HALs unfrozen is suitable for
platforms whos functionality is evolving and which do not require hard
gaurantees of cross version vendor/system interoperability.

Test: build owl
Bug: 109674659
Change-Id: Idc2a391b4bd7c2edbf9cdd7fc099b9d4a6fcf95a