For #14980 - Effectively disable tabs tray STATE_HALF_EXPANDED

[Mugurell]

STATE_HALF_EXPANDED cannot be disabled while also keeping fitToContents = true
based on which the tabs tray layout is currently set.
To work around this we'll set a a minuscule height for the tab tray when in this
state and then immediately advance to STATE_HIDDEN so to make it imperceptible
to the users.

video

Pull Request checklist

• Tests: No tests. Small UI changes in a not yet tested component.
• Screenshots: This PR includes screenshots or GIFs of the changes made.
• Accessibility: The code in this PR does not include any a11y user facing features.

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

[Amejia481]

The patch looks great, could we add test to verify the feature and avoid future regressions? :)

[Mugurell]

The patch looks great, could we add test to verify the feature and avoid future regressions? :)

I tried to but I think I'm gonna need some pointers.
With the code being in TabTrayView unit testing is troublesome.
TabTrayView can't be instantiated because of InflateExceptions (Robolectric doesn't have all of our Views), so the init can't be completed to be able to test the halfExpandedRatio set and also if a bottomSheetCallback is set or in our case what that anonymous one does.

[Mugurell]

There is a failing verifyContextMenuShortcuts ui test apparently unrelated to these changes.
Closing and reopening the ticket to rerun CI tasks.

[codecov-io]

Codecov Report

Merging #16052 into master will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master   #16052      +/-   ##
============================================
- Coverage     29.97%   29.97%   -0.01%     
+ Complexity     1203     1202       -1     
============================================
  Files           451      451              
  Lines         18463    18466       +3     
  Branches       2541     2542       +1     
============================================
  Hits           5535     5535              
- Misses        12500    12503       +3     
  Partials        428      428              

Impacted Files	Coverage Δ	Complexity Δ
...main/java/org/mozilla/fenix/tabtray/TabTrayView.kt	0.00% <0.00%> (ø)	0.00 <0.00> (ø)

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[Mugurell]

Added some UI tests for the changes here if unit testing doesn't work.
@Amejia481 @topotropic can you please re-review?

[Amejia481]

Sure!

[topotropic]

this PR will also fix #13777, thanks!