Camera VTS: Remove unnecessary test of Y16 depth format

getAvailableOutputStreams() shouldn't unconditionally add Y16 stream
configurations. Instead, if the threshold being passed in is valid,
getAvailableOutputStreams() should use the threshold's format
instead.

Test: Run VTS on pixel; vendor testing.
Bug: 265984260
Change-Id: I3c8119c6032141bb6e2f95f060f014a13340d16b