Added inav 7.1 related sounds (vtol, angle hold, ...)

Due to a change in googles text-to-speech library, the volume of newly generated sounds is lower than it used to be. I regenerated all sounds for this release.

I suggest replacing all sounds on your SD card with the ones in this release and increasing the "wav volume" by 1 notch in opentx/edgetx/freedomtx.