Make CellIdentity#getPlmn() Publicly Accessible

Add support for telephony to access getPlmn().

Bug: 148111627
Test: compilation (trivial)
Merged-In: I5a79e5339a7e4e1351582f199559801069df0c76
Change-Id: I5a79e5339a7e4e1351582f199559801069df0c76
(cherry picked from commit 741d281c60ae7a2958e71ec907f432ef2721fb4e)
1 file changed