Support partial module variants with apex_contributions

Some libraries like `libnativehelper_compat_libc++` only exist as shared
library in module sdk. When prebuilt of this library is selected using
apex_contritbutions, only shared linkages should be redirected to the
prebuilt version. The static linkage should come from source.

Test: Added a unit test
Bug: 322175508

Change-Id: Ic65d376b2354b4a42c7b9ea3ed1cd80c37e2840f