Locale: Retain compatibility with 4.4 APIs

Wrap the new methods from change I9b2d7f8d17f970d1b57111dcfe92c16e68b0fa67
in the previous public method.

Fixes libcore.icu.ICUTest#test_localeFromString

Change-Id: Icbffb5d5b55329f29c791b57d019817b5c298431