Enforce NETWORK_STACK permission for calling NSS#forceUpdateIfaces

ConnectivityManager and its usages are removed from
NetworkStatsService. After that, forceUpdateIfaces requires
information that only ConnectivityService has, hence
restricting the calling permission to NETWORK_STACK or
MAINLINE_NETWORK_STACK permission. The required permission
will be changed from READ_NETWORK_USAGE_HISTORY to
NETWORK_STACK or MAINLINE_NETWORK_STACK. This change would make
it impossible to call outside the system.

Bug: 126830974
Test: atest FrameworksNetTests
Change-Id: I776484921b2dbb6735d7940c558fb5e4baed6d1e