WifiPermissionsUtil: Add bypass for MAINLINE_NETWORK_STACK

Allow apps with privileged NETWORK_STACK & MAINLINE_NETWORK_STACK
permission to always access scan results & other location sensitive data.

Bug: 126775927
Test: Verified that captive portal page displays the SSID now.
Test: ./frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: I6bbb75984747059b2e30f468725bf5e887ce4899
2 files changed