Fix all-time dark Openboard settings for Android 12+

[BlackyHawky]

This PR fixes issue #751:
Describe the bug
On my device I'm using light mode, however, when opening the OpenBoard settings they are displayed in dark mode.

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I confirmed this bug on my Samsung Tablet with Android 13 too.

• Screenshot before:
  

• Screenshot after:
  

Of course, when you use your tablet in dark mode, the Openboard settings follow the dark mode:

  

[RHJihan]

Thanks. Tested on One UI 5.1 (Android 13). Works fine.

[Helium314]

Of course, when you use your tablet in dark mode, the Openboard settings follow the dark mode

Do you know why this is?
I would expect values-v31 (now explicitly using light theme) to take precedence over values-night-v21. But maybe I'm wrong here

[BlackyHawky]

Of course, when you use your tablet in dark mode, the Openboard settings follow the dark mode

Do you know why this is?
I would expect values-v31 (now explicitly using light theme) to take precedence over values-night-v21. But maybe I'm wrong here

Normally it's impossible for a phone with a version below Android 13 to choose the values-v31 folder settings.

I've just tested with my Android 10 phone and I can confirm that the blue color is different from the one defined in the platform-themes.xml file in the values-v31 folder.

I agree that it's strange that we don't need to create a values-night-v31 folder.
I haven't looked into it.