Add support for prebuilt java_sdk_library modules

Add java_sdk_library_import for use when a java_sdk_library may
be used by unbundled branches that do not have the project that
contains the original java_sdk_library module.

Bug: 130287656
Test: m checkbuild
Change-Id: I62df4bccc0da95ed6c8b31dab8f2c32cc3215e9e