Incorporate cc_library_shared into mixed builds

The infrastructure is already there via its need in
`cc_library`. Therefore, just enable it by setting
the `bazelHandler` in `LibrarySharedFactory`, and
add a test to verify the functionality.

Bug: 198817980
Test: cc/library_test.go:TestCcLibrarySharedWithBazel
Change-Id: Ibff80616632af59a0e409110f8645e028f99c7d6