Auto configure Rx OTA protocol from the Tx

[JyeSmith]

This is bit of a POC for changing the rx OTA protocol via the Tx.

This then opens up the question of should the Tx lua also contain the Protocol1 list and be used to configure the Rx?

Or should only OTA changes be sent, and the serial output config left on the Rx? In which case is another config setting required to restore the original non-mavlink protocol when changing back to Normal from Mavlink? Or is defaulting back the crsf ok?

[wvarty]

We (devs) change this setting a lot, but I bet most users would set the RX serial config once, and then rarely ever again... I think defaulting back to CRSF when switching from MAVLink back to Normal is probs fine...

[JyeSmith]

I think otaProtocol can be 1 bit ,unless you are thinking we may have other protocols in future.

Changed to 2 bits. I want to future proof a little while the bits are still unused.