Only going to use the defaultPhone instance if it is not null.

On boot, PhoneInterfaceManager would throw errors when it tried to use a null object on a hikey960 when it assumed there was a phone when in fact, there was not.

Merged-In: I16076b712ea53b5cbe9a2646b78ba5f515410beb
Bug: 129880602
Test: Flashed Hikey960 and no error on boot.
Change-Id: I16076b712ea53b5cbe9a2646b78ba5f515410beb
(cherry picked from commit 2d92f4903c5213a22fed6ce1dfcb9dc0b76c8ee9)
1 file changed