Keep "Hang Up" button on dialer

[minosimo]

Hello,

I have recently installed Simple Dialer on my grandmother's phone. Her one frustration occurs when trying to hang up a call after using the dial pad. She checks her voicemail by calling a number, and needs to open the dial pad to interact with the voicemail. When done, she looks on screen but does not see the hang up button, and does not know where to find it, which means she goes back to the home screen and gets stuck with a call running in the background.

I compared to the stock Graphene OS dialer, which maintains the hang up button in the dialpad. I believe the Google dialer must do this as well.

I am guessing that Simple Dialer hides the call button to keep compatibility with smaller screens, and to make it easier to dial with one hand, which I also appreciate. Would there be interest in a PR that addresses this? Is there any preference between an adaptive behavior, where the dialpad hides or shows the hang up button depending on screen size, or a toggle in options for "Show hang-up button on dialpad"?

[inson1]

@minosimo SMT apps were sold to ad company. SimpleMobileTools/General-Discussion#241
Fork is here https://github.com/FossifyOrg