Changes to support both androidx and support package

This includes the changes needed in layoutlib to support both androidx
and the "old" android.support namespaces. In most cases it's just a
matter of trying both names.

Test: Existing tests pass
Bug: 72540342
Change-Id: I91dbf39aade96b68817b8af51338da2284cae723
(cherry picked from commit a094e4734b1e3294f12e03e361cdb16e9a58e9de)