Fix null pointer crash in AIDL radio HAL VTS am: cf892db1ef am: e065f848d0

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/24133137

Change-Id: Iaa7cfd3e11d99fa6854423e70421db78817fbd21
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>