Only support explicitly approved Settings Slices,
dictated by controllers which return true for the new
method isSliceable.
Updating the supported settings to a whitelist means that
the method to return all available slices must be updated,
and checking slicability when we index slices.
Test: robotests
Bug: 79779103
Change-Id: Ib2b9690cdd0036b5cc4a1cb846c52bce7c824ab9
bf1f5b5813