Expose webext storage - Githubissues

Breaking changes: This PR follows our breaking change policy
- [ ] This PR follows the breaking change policy:
  - This PR has no breaking API changes, or
  - There are corresponding PRs for our consumer applications that resolve the breaking changes and have been approved
[ ] Quality: This PR builds and tests run cleanly
- Note:
- For changes that need extra cross-platform testing, consider adding [ci full] to the PR title.
- If this pull request includes a breaking change, consider cutting a new release after merging.
[ ] Tests: This PR includes thorough tests or an explanation of why it does not
[ ] Changelog: This PR includes a changelog entry in CHANGELOG.md or an explanation of why it does not need one
- Any breaking changes to Swift or Kotlin binding APIs are noted explicitly
[ ] Dependencies: This PR follows our dependency management guidelines
- Any new dependencies are accompanied by a summary of the due diligence applied in selecting them.

Branch builds: add [firefox-android: branch-name] to the PR title.

mozilla / application-services