Prevent darkMode overwrite by frontend_default_dark_theme

[spacegaier]

Breaking change

Proposed change

The active this.hass.themeSettings.darkMode selection got incorrectly overwritten in the following edge case:

You have defined backend themes via frontend_default_theme and frontend_default_dark_theme and the OS is set to "dark preferred". The logic inside _applyTheme() first determines the correct active dark mode (and applies the matching theme variant), but then a few lines later it got overwritten to dark because darkPreferred and this.hass.themes.default_dark_theme were true while darkMode can correctly be set to false, but "looses" in the boolean "||" operation.

That meant that if you have selected the "light" radio box in the theme selection (while "Backend-selected" is the theme name), the overall theme was the light one (since it got applied a few lines after the initial correct darkMode determination), but inside this.hass.themeSettings.darkMode we had the wrong value.

This problem was noticeable if in that configuration you go the HA general settings and you see that despite the light theme being used, the map of the location editor was in dark mode (since unless the caller provides a fixed darkMode value, <ha-map> uses the this.hass.themes.darkMode).

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io