settings(manifest): Add NETWORK_SETTINGS permission

This is needed for invoking some wifi/connectivity API's. For example,
we switched over using this permission to determine if an app is allowed
to modify any saved wifi network configuration on the device.

Bug: 64001841
Test: Able to forget networks created by SetupWizard.
Change-Id: I932226a74b12bf726a2445188953b1ec34523cf9
Merged-In: I932226a74b12bf726a2445188953b1ec34523cf9