SdkTestCore for non-updatable modules

Provides SdkTestCore/test_core_current sdk_version for non-updatable
modules that have their test scope dependent on test apis from
framework-minus-apex.

Ignore-AOSP-First: Change in topic with internal-first projects
Bug: 289776578
Test: m checkapi

Change-Id: I855346c01bb609e81b14dbdc13330315badc339e