Enable hiddenapi check for exportable stubs

This change modifies the dependencies of the hiddenapi to always depend
on the exportable stubs, instead of the currently utilized everything
stubs.

To support this, the full api surface exportable stubs are defined in a
separate change at the `frameworks/base` project. Note that the full api
surface exportable stubs are only used for the hiddenapi purpose, and
`sdk_version` continues to utilize the currently existing everything
stubs.

Currently, this feature is hidden behind the build flag
"RELEASE_HIDDEN_API_EXPORTABLE_STUBS". This feature will be fully
enabled once metalava fully supports handling of the flagged apis.

Test: ENABLE_HIDDENAPI_FLAGS=true m
Bug: 317426356
Change-Id: I109b7cd27b20ceffcdf1766ab8106b0c276be2b3