This is Google's Voice Access app with one change: the activation key saves itself. Press the key you want, let go, and it's set. Everything else is Google's app, unchanged.
DownloadFree · 5.7 MB · Android flip and keypad phones
The regular Voice Access asks you to pick an activation key, then press OK. On a phone with no touchscreen, pressing OK just picks a different key. You go in circles and nothing saves.
This copy skips the OK step. Press the key you want and let go. That's the only change.
Changed your mind? Press Back to leave without saving.
Installing on a keypad phone takes a computer and a USB cable, and the regular Voice Access has to come off first. If that's not your thing, send this page to whoever helps with your phone. Everything they need is on the technical page.
Tested on the Sonim XP3900.