Clear calling identity before accessing DeviceConfig am: d65aa4ba26

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/23160915

Change-Id: Ia45cdeb207f0596cd79a7df13231c92faa48140b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>