Drop special-casing of tv in source/prebuilt selection

Removal of this additional special-casing was missed in aosp/3028110

Test: presbumits
Test: used go/abtd to test a handful of targets in tv's release branch
Bug: 308188056
Change-Id: I6af3821f53e0ceeb0c48c921a0c851b9e6d2d5b6