Added switch to automatically follow the system theme

[newhinton]

This adds a toggle that decides the theme based on the system theme.

Edit: It is now the defaut setting

[x0b]

Seems like a good idea. How does this interact with the old toggle?

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Maybe you have a good idea for another situation? I "fixed" the OnboardingActivity (https://github.com/x0b/rcx/commit/be47536e94787c5627c92e5c7e48829c5c33053b) on some devices where the background & font came out as white, i.e. making the Onboarding View completely unreadable.

Since this happens on the first start, before the user can chose a theme, I tried to use a DayNight theme. Unfortunately, that didn't fix the issue with the white/white color combination. Do you have a good idea to follow the system there as well?

[newhinton]

It disables it in the ui and overrides it in code.

As far as i can see it, rcx handles theming on it's own, instead of using the system "way". Afaik we should define a color.xml for nightmode, and then use a system call to handle theming on its own. (which also should take care of the non themed popup menus) I think switching to that may help here aswell. All my devices are showing the problem you mentioned, and fixing theming was one of my tasks for later

[x0b]

It disables it in the ui and overrides it in code.

The dark theme switch, right? That's good, otherwise users might get confused.

I think switching to that may help here aswell.

I tried that by inheriting from a DayNight theme, and it did not work. I think it is the weird interaction between the RCX theming system, the AppIntro library and the DayNight mechanism. I don't think this is such a big issue though, that can be changed later.

Is this PR otherwise ready for review?