Use built SDK stubs

Now that the SDK stubs are built in Soong, undo the hack that
uses the prebuilt stubs.

Fix the linktype checks to treat the various stubs libraries as
the correct type, since they can't be annotated with sdk_version.

Bug: 70351683
Bug: 77285514
Test: m checkbuild
Change-Id: I5e870c34dd0ebc8ae3f888ec627da590c846a76f