Fixed mark-profile-owner-on-organization-owned-device for non-profile users

It was throwing a NPE as such users are "orphan".

Test: adb shell dpm mark-profile-owner-on-organization-owned-device com.afwsamples.testdpc/.DeviceAdminReceiver
Fixes: 182189140
Change-Id: Ib02d767a23c53c1c2886728c2f338628149f7868

services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java

@@ -13639,6 +13639,9 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         mInjector.binderWithCleanCallingIdentity(() -> {
             // Clear restriction as user.
             final UserHandle parentUser = mUserManager.getProfileParent(UserHandle.of(userId));
+            if (parentUser == null) {
+                throw new IllegalStateException(String.format("User %d is not a profile", userId));
+            }
             if (!parentUser.isSystem()) {
                 throw new IllegalStateException(
                         String.format("Only the profile owner of a managed profile on the"