[RESTRICT AUTOMERGE] Restrict WifiDialogActivity

- Don't show WifiDialogActivity if user has DISALLOW_ADD_WIFI_CONFIG

Bug: 299931761
Flag: None
Test: manual test with TestDPC
atest -c SettingsRoboTests:WifiDialogActivityTest

Merged-In: Icbb8f45922ded163208976be9c2816060dcf09f1
Change-Id: Icbb8f45922ded163208976be9c2816060dcf09f1
(cherry picked from commit 51fa3d79)