Enforce NETWORK_STACK permission for calling NSS#forceUpdateIfaces

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
Merged-In: I1b26dc64eaab2151e6885fd01cc5e8d4e18c4e60
Change-Id: I4ea421e4126a45f65d25fe0bec74243a3b20aeab
(cherry picked from commit 6b895dea25b4fca87d275bb78367411623ded1d4)