Tabs are always autoDiscardable

[petemill]

Fix faulty logic that would almost never have a tab become discarded automatically.
Fix #13547

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed. (Ask a Brave employee to help if you cannot access this document.)

Test Plan:

Reviewer Checklist:

• Request a security/privacy review as needed if one was not already requested.

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[codecov-io]

Codecov Report

Merging #13555 into master will decrease coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master   #13555      +/-   ##
==========================================
- Coverage   56.63%   56.59%   -0.04%     
==========================================
  Files         284      284              
  Lines       28731    28728       -3     
  Branches     4746     4744       -2     
==========================================
- Hits        16272    16260      -12     
- Misses      12459    12468       +9

Flag	Coverage Δ
#unittest	56.59% <100%> (-0.04%)	⬇️

Impacted Files	Coverage Δ
app/browser/tabs.js	23.68% <100%> (-0.21%)	⬇️
js/stores/appStoreRenderer.js	91.66% <0%> (-8.34%)	⬇️
app/renderer/components/reduxComponent.js	57.75% <0%> (-3.45%)	⬇️
js/stores/windowStore.js	28.46% <0%> (-0.3%)	⬇️

[bsclifton]

++

[bridiver]

++

[bsclifton]

master 75ec846
0.23.x 5f11d5a
0.22.x 4a7830d