Only reset global restriction owner on DO->PO for the right user

Bug:28972648
Change-Id: I4ef727205bbd8ec319672480bac7b519b33d2a58
diff --git a/services/core/java/com/android/server/pm/UserManagerService.java b/services/core/java/com/android/server/pm/UserManagerService.java
index 9d8ba12..b916790 100644
--- a/services/core/java/com/android/server/pm/UserManagerService.java
+++ b/services/core/java/com/android/server/pm/UserManagerService.java
@@ -1009,9 +1009,13 @@
                 // in getUserRestrictionSource on who set local policies.
                 mGlobalRestrictionOwnerUserId = userId;
             } else {
-                // When profile owner sets restrictions it passes null global bundle and we reset 
-                // global restriction owner userId.
-                mGlobalRestrictionOwnerUserId = UserHandle.USER_NULL;
+                if (mGlobalRestrictionOwnerUserId == userId) {
+                    // When profile owner sets restrictions it passes null global bundle and we
+                    // reset global restriction owner userId.
+                    // This means this user used to have DO, but now the DO is gone and the user
+                    // instead has PO.
+                    mGlobalRestrictionOwnerUserId = UserHandle.USER_NULL;
+                }
             }
             {
                 // Update local.