Merge "Null phone check when checking if radio is off for thermal mitigation." into sc-qpr1-dev am: 070541b7cc am: 5268864cab

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telephony/+/15531684

Change-Id: I35d897a61656473f2d039f15a5491f0e83848245