Remove unused priviliged signature permission am: 25a5eb9c2b

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2972592

Change-Id: I5a150a193333fd9437f9d5523f6d5bd0ea6248ef
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>