feat(android-setup): choose host port dynamically

[dbjorge]

Description of changes

This PR uses the portfinder NPM package to have our service configurator dynamically choose a free host port to bind to, rather than unilaterally choosing the same port hardcoded into the service.

The logic to use portfinder is pretty straightforward; the more complicated change was the corresponding update to removeTcpForwarding. I didn't want to break the existing behavior of being able to clean up old forwarded ports from past app launches, so rather than updating it to accept a number parameter, it instead uses ADB getForwardList to query for all host ports that are mapped to the hardcoded service port, and removes the forwarding entry for each of those.

This change should be transparent to an end user except that it eliminates a class of errors that could occur from port reuse during setup; no visual change.

Pull request checklist

• [n/a] Addresses an existing issue: #0000
• Ran yarn fastpass
• Added/updated relevant unit test(s) (and ran yarn test)
• Verified code coverage for the changes made. Check coverage report at: <rootDir>/test-results/unit/coverage
• 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

[DaveTryon]

Very nice!