Fix system service crash on radio session death. DO NOT MERGE

This is a partial cherry-pick from ag/7063548

Bug: 140203726
Test: adb shell am start -S -W -n com.android.car.radio/.RadioActivity
      (multiple times)

Change-Id: I6f16ff6eb82fca63c697d284fb3f45c2bb2be38c
1 file changed