icu4c: added MR0 symbols for backwards compatibility

This is needed for the glgps blob from enrc2b (and possibly others)

https://github.com/AospPlus/android_external_icu4c/commit/1e548e80b9db63d786f0fe1e36fb61b9bf3c3138

Change-Id: I02033008be12494f9505a132f63f945a99747c5b