vmsg: Avoid 'Upload' button

[weiss]

Right now, users must press two buttons to send a recorded voice message: The green tick and then the Upload button. I think it would improve the UX if the latter could be avoided, for two reasons:

1. Pressing two buttons to achieve a single effect seems way too much work 😄
2. The naming of the Upload button might be confusing (or even worrying) to end users, who may not be aware that uploading the message is our way of sharing it with (only) the contact/group.

As I understand it, the reason for the separate Upload button is allowing for playing back the recorded message after pressing the green tick. I think it would be nice if this was possible before pressing the green tick, so the green tick would upload the message directly. If this is not an option (or too much work), I'd suggest at least renaming the Upload knob to Send in order to address the second issue I mentioned.