soft version 2.32

Feature or issues
- Add silent OTA function
- The FMR's buzzer is dynamically modified based on the battery voltage
- Prohibit OTA and FMR from working at the same time
- The backlight time is changed from 3 seconds to 5 seconds

bug: N/A
test: manual
Change-Id: Id29b2718db3b7c6f86b245d8e03c3b051142891f