Modified CTS KeyguardDisabledFeaturesTest

* Modified CTS tests to test setting the restriction
  KEYGUARD_DISABLE_SECURE_NOTIFICATIONS.
* Tested the KEYGUARD_DISABLE_SECURE_NOTIFICATIONS
  restriction to ensure it can be set on the parent
  profile when called by the profile owner of an
  organization-owned managed profile.

Bug: 149007069
Test: Manual testing with TestDPC
      atest com.android.cts.devicepolicy.OrgOwnedProfileOwnerTest#testSetKeyguardDisabledFeatures
      atest com.android.cts.devicepolicy.MixedDeviceOwnerTest#testSetKeyguardDisabledFeatures
      atest com.android.cts.devicepolicy.MixedManagedProfileOwnerTest#testSetKeyguardDisabledFeatures
      atest com.android.cts.devicepolicy.MixedDeviceOwnerTest#testSetKeyguardDisabledFeaturesLogged

Change-Id: I4c2e42d31e19efd78204a665fb1d64d0b43e275f