Add RTL layout support

[triallax]

What is it?

• Feature (user facing)

Description of the changes in your PR

Add RTL layout support to NewPipe.

Based on #3488 by @Royosef (thank you for your work!). Differences:

• Fixed merge conflicts
• Removed RTL handling from AboutActivity, since ViewPager2 supports RTL natively
• Other minor refactors

Issues to fix:

• Dialog action buttons should be reversed in order
• Broken with YouTube's Fast Forward/Rewind behavior #4833
• fast-forward/reverse seek in player (double taps) are not reversed accordingly seekbar isn't flipped anymore, so this isn't necessary (it might be necessary to investigate the player more closely in general)

Before/After Screenshots/Screen Record

Before	After

Fixes the following issue(s)

• Fixes RTL UI for rtl languages such as ckb,ku,ar,urdu...etc #3882

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.

Due diligence

• I read the contribution guidelines.

NOTE: SQUASH MERGE

[triallax]

Regarding this suggestion from #3488:

I'd merge LocalizeLayoutUtils (used to know if the device should be RTL and one method around that) and AndroidTvUtils to DeviceUtils.

I don't think we should merge LocalizeLayoutUtils into DeviceUtils. It doesn't make sense to call a device RTL; that's a description for a language script. Also, if the user chooses a language in NewPipe different from their system's, then it's not really related to their device anymore.

[opusforlife2]

It doesn't make sense to call a device RTL

Indeed.

[triallax]

The CI is failing because of this line:

NewPipe/app/src/androidTest/java/org/schabi/newpipe/local/history/HistoryRecordManagerTest.kt

Line 71 in dd9772c

assertTrue(entries[2].hasEqualValues(entities[0]))

On first look this doesn't seem to be related to the PR, but no such failure is present on dev, so either the test is flaky, or I've messed up something.

Edit: this is probably #7553.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

0.0% Coverage
0.0% Duplication

[triallax]

So the only issue I found so far with my PR is this:

In both screenshots, NewPipe's language is Arabic, but in the first one, the system language is English, while in the second it's Arabic. As you can see, the buttons are in different positions. I've checked with some other apps (e.g. Tasks) and they don't seem to exhibit this issue (i.e. they behave as the second screenshot when in RTL).

Do you think this is a blocker?

[triallax]

If I want to always use LTR in certain places, is it better to use left and right, or should I use start and end but with android:layoutDirection="ltr"?

[Stypox]

@mhmdanas probably left and right so that only the things that you specify are affected, otherwise (I think) android:layoutDirection="ltr" would propagate to all attributes and children. Unless you just want the latter ;-)

Do you think this is a blocker?

No, but if you find a way to solve it it's better ;-)

[triallax]

The player is too complicated for me to touch in this PR, so I'll try to leave it as-is for now, and perhaps open an issue when this PR is merged.

[triallax]

I don't think I'll be picking this up, so I'll be closing it (though I'd be happy to see someone else finish up the work).