feature(remove-android): Remove codec tests (#6751)

#### Details

Deprecating Android support will touch hundreds of files, so we're
breaking it up into more manageable units. This PR removes the files
under `src/tests/miscellaneous/codecs`. These tests were added as a
guard against accidentally shipping an Electron bundle that included
proprietary codecs. Now that we no longer ship Electron, we no longer
need the tests.

##### Motivation

Android deprecation feature

##### Context

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#### Pull request checklist
<!-- If a checklist item is not applicable to this change, write "n/a"
in the checkbox -->
- [n/a] Addresses an existing issue (part of Android deprecation
feature)
- [x] Ran `yarn fastpass`
- [x] Added/updated relevant unit test(s) (and ran `yarn test`)
- [x] Verified code coverage for the changes made. Check coverage report
at: `<rootDir>/test-results/unit/coverage`
- [x] PR title *AND* final merge commit title both start with a semantic
tag (`fix:`, `chore:`, `feat(feature-name):`, `refactor:`). See
`CONTRIBUTING.md`.
- [n/a] (UI changes only) Added screenshots/GIFs to description above
- [n/a] (UI changes only) Verified usability with NVDA/JAWS