feature: battery charging limiter (caps the max charge percentage to extend life of device batteries)

Created by: Osndok

Description of the feature

An option in battery settings to adjust the upper charging limit.

Background

I was watching this particular youtube video that concluded the best course of action to extend a phone's battery is only available to rooted android phones: setting an automatic charge limit.

Batteries are critical to mobile devices, and battery longevity is extra-critical to ubports for the following reasons:

• batteries fade over time
• we already support devices for which you cannot purchase new batteries
• we don't have the resources to constantly chase "the latest device"

I don't know what this looks like at a low level, but it could be as simple as writing an integer to a special hardware register.

Illustrations