systemui: Add CONNECTIVITY_INTERNAL permission

 * SystemUI needs to be able to list interfaces if tethering is in use
   and we ask for a second tethering path to be set up (BT+USB, etc).
 * Add permission to stop exceptions in the framework and enable
   tethering thru multiple paths.

Change-Id: If7a65c31557dc2f0451f0612fb109f61e8056368
BT: Fix memory leak when BT on & off done many times

Solves a memory leak in BatteryStatsService when Bluetooth
is turn on/off. Solution adds missing close of proxy then
Bluetooth is turned off.

Change-Id: I65f9db298459c7c15f6a10c752992f1d38469445
CRs-Fixed: 476145