Add a way to disable Bluetooth on the band

[sschuberth]

Apparently, there is a way to disable Bluetooth on the Band, and doing so significantly increases battery life in my tests. I have two Bands, and while both are added to the original mobile app, only either one is active in the app. The deactivated Band shows a crossed out Bluetooth icon on its display, and that Band has a much longer running time. However, I can only switch between active Bands in the app, and not deactivate both. If I disconnect them, then the Bands do not even show the time anymore and want to get paired first.

So what I'm looking for is a way for the Band to display the time and work "offline", while having Bluetooth disabled (as indicated via the icon on the display) to safe battery. I just want to use them as plain watches. It would be great if this tool would support putting Bands into this mode.

[sschuberth]

I just now found the instructions at https://codeberg.org/Freeyourgadget/Gadgetbridge/wiki/Huami-Server-Pairing#preparations to work for me, also from an iPhone 🎉 The key is to not unpair the Band from the app, kill the app, and then "forget" the Band from the operating system's Bluetooth device settings. Now both my Bands show the crossed out Bluetooth icon as expected 😁

[sschuberth]

Interestingly, the second Band where I disabled Bluetooth with the OSes "forget" option still discharges way faster than the other device (both were at 100% yesterday, now it's at 50% whereas the other one is at 99%), so something else must be going on 🤷🏻