fix(app, ios-config): use fully-specified path for /usr/bin/head

[mikehardy]

Description

It appears we have an expectation about what head binary will do,
and XAMMP at least bundles a different head which does not meet our
expectations.

This is a basic unix utility on all macs via the base install, so the full path to the
base install version should be a reasonable fix

Related issues

Fixes #5801

Release Summary

conventional commit

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
  • Yes
• My change supports the following platforms;
  • Android
  • iOS
• My change includes tests;
  • e2e tests added or updated in packages/\*\*/e2e
  • jest tests added or updated in packages/\*\*/__tests__
• I have updated TypeScript types that are affected by my change.
• This is a breaking change;
  • Yes
  • No

Test Plan

CI should show it works

---

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[codecov]

Codecov Report

Merging #5805 (4d2e33a) into master (6f435cf) will not change coverage.
The diff coverage is n/a.

❗ Current head 4d2e33a differs from pull request most recent head 87bff4a. Consider uploading reports for the commit 87bff4a to get more accurate results

@@            Coverage Diff            @@
##             master    #5805   +/-   ##
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  Coverage     53.14%   53.14%           
  Complexity      620      620           
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  Files           208      208           
  Lines         10071    10071           
  Branches       1542     1542           
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  Hits           5351     5351           
  Misses         4464     4464           
  Partials        256      256