Make setAirplaneMode @SystemApi for SetupWizard.

Expose ConnectivityManager#setAirplaneMode and the
NETWORK_SETUP_WIZARD permission so that SetupWizard can call
setAirplaneMode.

Delete setAirplaneMode from the greylist because the permissions
checks on it, since at least 2013, have been for a privileged
permission (CONNECTIVITY_INTERNAL) that normal apps don't have.

Test: m
Bug: 115302596
Change-Id: I28f24d32c4b4b386407e9e0e3514ea9f8854f4a8
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 73bb1fc..22194cc 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1441,6 +1441,7 @@
 
     <!-- Allows SetupWizard to call methods in Networking services
          <p>Not for use by any other third-party or privileged applications.
+         @SystemApi
          @hide This should only be used by SetupWizard.
     -->
     <permission android:name="android.permission.NETWORK_SETUP_WIZARD"