Reinstate CHANGE_NETWORK_STATE as a normal permission.

This is a partial revert of http://ag/738523 , but not a full
revert because M apps that have gone through the WRITE_SETTINGS
route to obtain permission to change network state should
continue to have permission to do so.

Specifically:

1. Change the protection level of CHANGE_NETWORK_STATE back from
   "signature|preinstalled|appop|pre23" to "normal". This allows
   apps that declare CHANGE_NETWORK_STATE in their manifest to
   acquire it, even if they target the M SDK or above.
2. Change the ConnectivityManager permission checks so that they
   first check CHANGE_NETWORK_STATE, and then ask Settings
   if the app has the WRITE_SETTINGS runtime permission.
3. Slightly simplify the code in the Settings provider code that
   deals specifically with the ability to change network state.
4. Make the ConnectivityService permissions checks use the
   ConnectivityManager code to avoid code duplication.
5. Update the ConnectivityManager public Javadoc to list both
   CHANGE_NETWORK_STATE and WRITE_SETTINGS.

Bug: 21588539
Bug: 23597341
Change-Id: Ic06a26517c95f9ad94183f6d126fd0de45de346e

1 files changed, 1 insertions, 4 deletions

diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 3860005..327fb8a 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -1447,10 +1447,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
     }
 
     private void enforceChangePermission() {
-        int uid = Binder.getCallingUid();
-        Settings.checkAndNoteChangeNetworkStateOperation(mContext, uid, Settings
-                .getPackageNameForUid(mContext, uid), true);
-
+        ConnectivityManager.enforceChangePermission(mContext);
     }
 
     private void enforceTetherAccessPermission() {