Clear calling identity before accessing DeviceConfig am: afda1a5579

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

Change-Id: Ib2adc87f87de2556e19b59dbc37820c4ae0d9e09
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>