Remove INTERACT_ACROSS_USERS_FULL for NetworkStack

Replace with INTERACT_ACROSS_USERS, which is needed to send the
ACTION_NETWORK_CONDITIONS_MEASURED broadcast.

Also cleanup some non-privileged permissions that were added to the
priv-app file.

Test: built, booted, broadcast and captive portal login work
Bug: 123846255
Change-Id: I3c97c166e80c19bf57fa047709c8b91fca75d635