Fix Routeractivity theming

[litetex]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

When the app is not running in the foreground and started via RouterActivity (e.g. clicking/sharing a link to NewPipe) incorrect things start to happens:

• The UI has incorrect colors (seen in Download popup file already exists action buttons display issue #8179)
  • The day/night mode of the app is ignored
• The language is the device language

Why does this happen?

• The RouterActivityThemes are overriding the color*-attributes (colorPrimary, colorPrimaryDark, ...). I'm not sure why this was done in the first place, however it causes the theming issues on the UI.
• RouterActivity misses some code from MainActivity, e.g. assureCorrectAppLanguage and ThemeHelper.setDayNightMode. This causes further problems like the incorrect language or wrong colored theme elements.

Before/After Screenshots/Screen Record

Done via the test manual below:

• Before:
  

• After:
  

Fixes the following issue(s)

• Fixes Download popup file already exists action buttons display issue #8179; maybe more issues, hard to check when there are >1k open ones

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR.

Test manual

• Change theme to dark
• Change the app-language to something other then the phone-languguage (e.g. German)
• Restart the app (so that the language is applied)
• Close the app completely
• Share a stream link to NewPipe (that you never watched before)
• the ask what to do dialog should come up
• click add to playlist

Due diligence

• I read the contribution guidelines.

[Stypox]

Why don't you remove all RouterActivity themes and use the app's ones?

Add to playlist is not implemented inside DownloadDialog ??? #7194

What?

[litetex]

@Stypox

Why don't you remove all RouterActivity themes and use the app's ones?

These themes hides/makes the app transparent (e.g. windowBackground).
If I use the normal themes you see half of the app in the background which wouldn't be good in my opinion.

Add to playlist is not implemented inside DownloadDialog ??? #7194
What?

PR No2 is already work in progress to fix that 😆

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[Redirion]

your last commit message is misleading, as it actually still is a static method :D