Improve behaviour of preset of video quality

The other side or me frequently are not equipped (hardware- or bandwith-wise) to receive or transmit HD video. It will pass some time before one can (reliably) rely on this being detected and adjusted automatically and on-the-fly (at which point, the manual toggle will likely change).

In the current situation it would be beneficial if either...

* the default can be set to either HD or SD in the settings
* the setting from the last call is remembered

Both options would help with convenience, so the setting doesn't have to reset to the desired value repeatedly. It would also be of greater importance for users (less technically inclined or invested in the app) who are challenged to remember to do this every time.

Thank you!