For #6832: fix unattached context crash in HomeFragment

[severinrudie]

Pull Request checklist

• Tests: This PR includes thorough tests or an explanation of why it does not
• Screenshots: This PR includes screenshots or GIFs of the changes made or an explanation of why it does not
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features

After merge

• Milestone: Make sure issues finished by this pull request are added to the milestone of the version currently in development.

To download an APK when reviewing a PR:

1. click on Show All Checks,
2. click Details next to "Taskcluster (pull_request)" after it appears and then finishes with a green checkmark,
3. click on the "Fenix - assemble" task, then click "Run Artifacts".
4. the APK links should be on the left side of the screen, named for each CPU architecture

[codecov-io]

Codecov Report

Merging #7509 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #7509      +/-   ##
============================================
- Coverage     19.21%   19.21%   -0.01%     
  Complexity      449      449              
============================================
  Files           298      298              
  Lines         11418    11419       +1     
  Branches       1536     1537       +1     
============================================
  Hits           2194     2194              
- Misses         9056     9057       +1     
  Partials        168      168

Impacted Files	Coverage Δ	Complexity Δ
...c/main/java/org/mozilla/fenix/home/HomeFragment.kt	0% <0%> (ø)	0 <0> (ø)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update aa3a32b...4fba3cd. Read the comment docs.