Clear calling identity before accessing DeviceConfig am: afda1a5579 am: 651f10b65d am: da99c8abad

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2584072

Change-Id: I76ee9156b5a998a58e0f2d7cfd3000eebad125c5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>