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

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

Change-Id: I622159e78d53a8163a9b87f74d2cae4ba1f3550f