[RESTRICT AUTOMERGE] Fix NullPointerException when mLockPatternUtils is not set.

Test: atest LockTaskControllerTest
Bug: 132593073
Change-Id: I1bfacd5992569d67cdaa526b18d1c426a366babb
(cherry picked from commit fa1b986746)

services/core/java/com/android/server/am/LockTaskController.java

@@ -794,7 +794,7 @@ public class LockTaskController {
         } catch (Settings.SettingNotFoundException e) {
             // Log to SafetyNet for b/127605586
             android.util.EventLog.writeEvent(0x534e4554, "127605586", -1, "");
-            return mLockPatternUtils.isSecure(USER_CURRENT);
+            return getLockPatternUtils().isSecure(USER_CURRENT);
         }
     }