We cannot always request new permissions when Dialer UI is shown. For
example, Dialer UI can be shown over keyguard, which doesn't allow other
dialogs (like the permission request dialog) to be displayed. However it
doesn't return the failed response either, making ConnectionService kind
of stuck.
If we just do not use the Dialer UI when the permission is not granted,
it is at most a minor annoyance for the first time. After the user has
accepted an incoming call even just once, the permission will be
granted, and the Dialer integration will start to work just fine.
Peter Cai
0f581f889a