feat(sync): pull feature flags when online [WPB-5403]

[vitorhugods]

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PR Submission Checklist for internal contributors

• The PR Title

  • conforms to the style of semantic commits messages¹ supported in Wire's Github Workflow²
  • contains a reference JIRA issue number like SQPIT-764
  • answers the question: If merged, this PR will: ... ³

• The PR Description

  • is free of optional paragraphs and you have filled the relevant parts to the best of your ability

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What's new in this PR?

Issues

On big teams, the user may not be notified when feature flags change.

Causes

Backend limitation.

Solutions

Fetch every 1h or so, when becoming online.

Rely on similar mechanisms that we already have for uploading keypackages and prekeys, for example: observe incremental sync status.

This way, when the app becomes online, it will fetch the feature configs if:

• The app was killed and reopened, or
• The last feature configs fetch was more than 1h ago

Testing

Test Coverage

• I have added automated test to this contribution

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PR Post Merge Checklist for internal contributors

• If any soft of configuration variable was introduced by this PR, it has been added to the relevant documents and the CI jobs have been updated.

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References

1. https://sparkbox.com/foundry/semantic_commit_messages
2. https://github.com/wireapp/.github#usage
3. E.g. feat(conversation-list): Sort conversations by most emojis in the title #SQPIT-764.

[github-actions]

Unit Test Results

   413 files     413 suites   23s ⏱️
2 269 tests 2 149 ✔️ 120 💤 0 ❌

Results for commit 469c4ac.

♻️ This comment has been updated with latest results.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (release/candidate@2ae885d). Click here to learn what that means.
The diff coverage is n/a.

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  Hits                         ?    21986           
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