Fixed notifyUnsafeOperationStateChanged.

It was always sending the notification to the DO, even when it wasn't
set.

Test: atest com.android.cts.devicepolicy.ProfileOwnerTest#testDevicePolicySafetyCheckerIntegration_unsafeStateException,testDevicePolicySafetyCheckerIntegration_allOperations,testDevicePolicySafetyCheckerIntegration_isSafeOperation,testAdminActionBookkeeping,testDevicePolicySafetyCheckerIntegration_onOperationSafetyStateChanged

Fixes: 180922138

Change-Id: I474a1026999296ccff1e64d5cc302af4178ce201