Allow OnCancelListener and OnDismissListener in Settings app

for the framework-managed dialogs.

DialogFragment acts as both listeners so the application cannot set both
listeners in the embedded dialog. New hooks are added in SettingsDialogFragment
so that settings apps can do so for the framework-managed dialogs.

Bug: 3386670
Change-Id: I144e7c4ccf7f86c61f6079fa86d830c709335af1