An action block that awaits a spoken hotword.
The fiber will pause until the user has spoken the keyphrase.
Hotword detection requires dedicated hardware and system software which may not be available on all device. Currently the only supported keyphrase is “OK Google”, the Google (Now) app may have to be installed.
Note! This feature require Android 6+. May no longer work as the API used seems to not have been meant for app usage, although is was public, but has now been made inaccessible.