Add skin tone picker to the emoji picker

[bxdxnn]

Content

Motivation and context

Fixes #5859

Feature parity with Element Classic and it has been frequently requested.

Screenshots / GIFs

Tests

• Hold an emoji with a badge on it, then hover a tone

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• I am aware of the etiquette.
• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly defines what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

[github-actions]

Thank you for your contribution! Here are a few things to check in the PR to ensure it's reviewed as quickly as possible:

• If your pull request adds a feature or modifies the UI, this should have an equivalent pull request in the Element X iOS repo unless it only affects an Android-only behaviour or is behind a disabled feature flag, since we need parity in both clients to consider a feature done. It will also need to be approved by our product and design teams before being merged, so it's usually a good idea to discuss the changes in a Github issue first and then start working on them once the approach has been validated.
• Your branch should be based on origin/develop, at least when it was created.
• The title of the PR will be used for release notes, so it needs to describe the change visible to the user.
• The test pass locally running ./gradlew test.
• The code quality check suite pass locally running ./gradlew runQualityChecks.
• If you modified anything related to the UI, including previews, you'll have to run the Record screenshots GH action in your forked repo: that will generate compatible new screenshots. However, given Github Actions limitations, it will prevent the CI from running temporarily, until you upload a new commit after that one. To do so, just pull the latest changes and push an empty commit.

[bxdxnn]

• If your pull request adds a feature or modifies the UI, this should have an equivalent pull request in the Element X iOS repo

BTW, I'm not sure about this one, because in most cases (e.g. even for a large feature that obviously needs parity like MSC implementations) the iOS team is doing their own development even if you submit a PR.
It's also much harder for me to do iOS development. so please explicitly ask that feature parity with iOS is required to be done by myself, as ATM it doesn't seems to be this way.

[jmartinesp]

@mxandreas I think we need some product decision here too. FWIW, it LGTM with a couple of tweaks.

[mxandreas]

@mxandreas I think we need some product decision here too. FWIW, it LGTM with a couple of tweaks.

Can you provide a demo video?

[jmartinesp]

@mxandreas I think we need some product decision here too. FWIW, it LGTM with a couple of tweaks.

Can you provide a demo video?

Sure. Long pressing an emoji with skin tone variants opens a pop-up where you can select a skin tone by sliding left/right, or cancel it by scrolling vertically outside the pop-up. If you long press in an emoji that doesn't have skin tones, it'll just add it as if you tapped on it.

Screen_recording_20260602_101402.mp4

[mxandreas]

Thanks, LGTM.