Fixed a NullPointerException in AccountManagerService.

Change-Id: If65d7870c609ae6c7467e26978ffd0ce0d52f518
diff --git a/services/core/java/com/android/server/accounts/AccountManagerService.java b/services/core/java/com/android/server/accounts/AccountManagerService.java
index 9a86136..2a66baf 100644
--- a/services/core/java/com/android/server/accounts/AccountManagerService.java
+++ b/services/core/java/com/android/server/accounts/AccountManagerService.java
@@ -3144,6 +3144,9 @@
         DevicePolicyManager dpm = (DevicePolicyManager) mContext
                 .getSystemService(Context.DEVICE_POLICY_SERVICE);
         String[] typesArray = dpm.getAccountTypesWithManagementDisabledAsUser(userId);
+        if (typesArray == null) {
+            return true;
+        }
         for (String forbiddenType : typesArray) {
             if (forbiddenType.equals(accountType)) {
                 return false;