fb: TRDS change auto detect light conditions method 

Currently on critical light conditions it still switches to often between
on and off which results in bad UX and in worse cases to unusable phone
due that it is permanently switching. To prevend that slacken the light mode
level detection and set it when it goes to dark mode way more higher (LIGHT_OVERCAST)
and when into light mode back to lower level (LIGHT_FULLMOON)

PS
- change to LIGHT_OVERCAST, 20.000 lux was to high lol