Dependencies through jcenter

[stevenzeck]

The jcenter() repository was originally going to be completely unavailable starting early 2022, but that has since changed in that it will now be read only indefinitely. See https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/. However, that means that existing dependencies won't be getting updates through it. Here are the dependencies all of the modules use that are only available through jcenter:

1. com.github.barteksc:android-pdf-viewer: Used in the Navigator module. According to the readme, they're actively looking for a new maintainer, so unless someone picks it up I also don't expect it to be moved from jcenter.
   2. com.shopgun.android:utils: Used in the Navigator module. Only used in one file, R2FXLLayout, so maybe this can be replaced natively?
   3. com.duolingo.open:rtl-viewpager: Used in the Navigator module. This is no longer maintained and should be replaced by ViewPager2.

[mickael-menu]

1 is tricky, but could be made less critical by extracting the PDF navigator into a dedicated module. This work was started in #67.

2 and 3 will not be part of Navigator 2, so it will sort itself out.

[stevenzeck]

Really need to take a hard look at this sooner than later...

[mickael-menu]

For reference, regarding today's incident: https://status.gradle.com/incidents/c65zmfw32lpm

[qnga]

A fork of android-pdf-viewer has been published on Maven Central. It will be worth a look if we can solve the incompatibility between liblcp and recent versions of PDFium. As liblcp development has started again, a new hope has risen!