Updating BT firmware - beginning of upgrade process on Arduino RP2040

[benjaminaigner]

On the FM3 board with the Arduino RP2040 Connect, the Bluetooth update process fails sometimes,
because the receiving of "OTA:ready" is mixed up with esp-idf console output.

Because we are limited to the pins connected by the Arduino board, we are using UART0
for transmitting our data (HID, commands,...) as well as the esp-idf logging output.

Especially when using the OTA firmware to write a new BT firmware, the outputs get mixed up.
Not really mixed up, but there is a newline missing after the logging output.

And if the "OTA:ready" is not at the beginning of a line, the detection fails in the webgui.

Suggestion:

Change the waitForReceiving function from a complete comparison to a "contains" like check.
Or an additional function just for "OTA:ready" which checks if this string is contained in the received string.