Fix issue #3289835: NullPointerException in...

..PackageManagerService.grantPermissionsLP when updating system app

Change-Id: I36c1b96d2fe9a8737843d30f3a2669935fc281bb

services/java/com/android/server/PackageManagerService.java

@@ -5699,7 +5699,10 @@ class PackageManagerService extends IPackageManager.Stub {
         res.removedInfo.removedPackage = packageName;
         // Remove existing system package
         removePackageLI(oldPkg, true);
-
+        synchronized (mPackages) {
+            mSettings.disableSystemPackageLP(packageName);
+        }
+        
         // Successfully disabled the old package. Now proceed with re-installation
         mLastScanError = PackageManager.INSTALL_SUCCEEDED;
         pkg.applicationInfo.flags |= ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;