This commit breaks up the code in `deploy-to-firebase.js` script, that
we use for deploying angular.io to production, to smaller functions
(instead of a monolithic block). This makes the script easier to
maintain and also makes testing individual operations easier.
The commit also updates the `deploy-to-firebase.spec.js` spec file to
take advantage of the standalone functions to speed up testing by
calling the corresponding function instead of having to spawn a new
process and run the `deploy-to-firebase.js` script with the `--dry-run`
flag.
NOTE: Before updating the tests, I verified that the updated
`deploy-to-firebase.js` script passed the old tests.
PR Close#39470
699824a2a5