Use getter instead of member for IEuiccController stub.

Make EuiccManager robust to com.android.phone process death.

Bug: 64150969
Test: Tested on two walleye devices. One contains the fix, and the other
one doesn't. Use kill -9 PID. The one with the fix can continue work
(the phone process is up quickly after gets killed), while the other one
doesn't work unless restart LPA.
Change-Id: I67649e31381f1c2b6f187d86684b22a000e6e0b0