I'm developing an application where I do not want the keyboard in text fields to be replaced by a third party one that a user has installed. I want the system one to be always used. Alternatively, a custom one included with my app to be always used.
Does anyone know how this can be achieved?
You cannot control what keyboard the user uses within your app on Android, sorry.
At best, you could always make the user use your keyboard, but then you'd have to extend and customize every UI component that accepts input to show your keyboard when clicked instead.