Start userId from 10, reserving 1-9 for special use in the future.

Change-Id: I3d0c1717d8b3add75ba43ed98e53ba02e6682c34

Author: Amith Yamasani

services/java/com/android/server/pm/UserManagerService.java

@@ -688,7 +688,7 @@ private void updateUserIdsLocked() {
      */
     private int getNextAvailableIdLocked() {
         synchronized (mPackagesLock) {
-            int i = 0;
+            int i = 10;
             while (i < Integer.MAX_VALUE) {
                 if (mUsers.indexOfKey(i) < 0) {
                     break;