Make sure the bottom toolbar is never stuck invisible

[miDeb]

Closes #7101. This is my attempt to solve this issue. Essentially, if the user is scrolling upwards, but the toolbar is not being scrolled and not already showing or animating up, just forceExpand it.

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Pull Request checklist

• Quality: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry or does not need one
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features

After merge

• Milestone: Make sure issues closed by this pull request are added to the milestone of the version currently in development.
• Breaking Changes: If this is a breaking change, please push a draft PR on Reference Browser to address the breaking issues.

[codecov]

Codecov Report

Merging #7102 into master will increase coverage by 0.00%.
The diff coverage is 60.00%.

@@            Coverage Diff            @@
##             master    #7102   +/-   ##
=========================================
  Coverage     77.01%   77.02%           
- Complexity     4899     4903    +4     
=========================================
  Files           654      654           
  Lines         24150    24165   +15     
  Branches       3543     3546    +3     
=========================================
+ Hits          18599    18612   +13     
  Misses         4062     4062           
- Partials       1489     1491    +2     

Impacted Files	Coverage Δ	Complexity Δ
...r/toolbar/behavior/BrowserToolbarBottomBehavior.kt	78.33% <60.00%> (-1.67%)	27.00 <0.00> (+3.00)	⬇️
...lla/components/support/migration/AddonMigration.kt	96.05% <0.00%> (+0.59%)	11.00% <0.00%> (+1.00%)

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[Mugurell]

Thank you @miDeb , the patch looks good!
I see some CI tasks failed because of missing dependencies, closing and reopening the PR just to have them run again.

[Mugurell]

Thank you @miDeb !
Indeed, there are some edgecases described here https://bugzilla.mozilla.org/show_bug.cgi?id=1633322 for which we don't really have a solution.
Ignoring the GV state for this particular edgecase seems like the best approach in the meantime to make sure users cannot be stucked without a toolbar.
Nice patch 👍!

[jonalmeida]

bors r=Mugurell

[bors]

Build succeeded:

• complete-push

[miDeb]

Thank you!