Change Firebase device for UI tests

[rpappalax]

This PR attempts to address test flakiness in the findInPage test which is probably restricted to a virtual device irregularity. Also, moving num-flaky-test-attempts to proper config position although NOTE: this appears to be busted at the moment. I've filed:
Flank/flank#603

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
• 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.

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[codecov-io]

Codecov Report

Merging #5620 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #5620   +/-   ##
=========================================
  Coverage     14.02%   14.02%           
  Complexity      308      308           
=========================================
  Files           256      256           
  Lines         10490    10490           
  Branches       1522     1522           
=========================================
  Hits           1471     1471           
  Misses         8902     8902           
  Partials        117      117

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