Radio: get service by value.

Get strong pointer to service interface by value and not reference to
prevent race conditions where the service pointer can be cleared
by another thread while in use.

Bug: 30907212
Change-Id: Iae838b3b672562c1d0cd63968399a6bfdda7f5ab
(cherry picked from commit 28a0e9ec)
(cherry picked from commit bd04b47d38a89f1dada1c6da2ef4a3d235c166b8)