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

Change-Id: I3d0c1717d8b3add75ba43ed98e53ba02e6682c34
diff --git a/services/java/com/android/server/pm/UserManagerService.java b/services/java/com/android/server/pm/UserManagerService.java
index a58c4ea..ca2236f 100644
--- a/services/java/com/android/server/pm/UserManagerService.java
+++ b/services/java/com/android/server/pm/UserManagerService.java
@@ -688,7 +688,7 @@
      */
     private int getNextAvailableIdLocked() {
         synchronized (mPackagesLock) {
-            int i = 0;
+            int i = 10;
             while (i < Integer.MAX_VALUE) {
                 if (mUsers.indexOfKey(i) < 0) {
                     break;