Switch last c.a.i18n.phonenumbers hiddenapi entries to annotations

Previous changes could not remove these entries as they are implicit
methods, i.e. are not present in the source, and so could not be
annotated. That is no longer true and so these entries can now be
removed.

This was tested by making and then manually checking that the generated
out/target/common/obj/PACKAGING/hiddenapi-light-greylist.txt was the
same (after sorting) before and after this change.

Bug: 117818301
Bug: 119861512
Test: as above
Change-Id: Ic33c693f50cac011332c5ba5a5c0e2b6562e6ef8