Whether taking that context into account is a good idea is very debateable. The more contextually 'intelligent' a system is, the harder it is for the user to m

Whether taking that context into account is a good idea is very debateable. The more contextually 'intelligent' a system is, the harder it is for the user to model it, and ease of user modelling is often more important than reducing the number of interactions need to complete a task. In this particular case, it wouldn't be possible to know if your keyboard sequence that quits a call would feature an unnecessary enter at the end or not.