Format all files

[guidezpl]

This is what formatting all files and re-organizing imports does to all files, with the following additional changes

• revert firebase.json
• revert edits where imports would change docregion

Description of what this PR is changing or adding, and why:

Issues fixed by this PR (if any): #12498

PRs or commits this PR depends on (if any):

Presubmit checklist

• If you are unwilling, or unable, to sign the CLA, even for a tiny, one-word PR, please file an issue instead of a PR.
• If this PR is not meant to land until a future stable release, mark it as draft with an explanation.
• This PR follows the Google Developer Documentation Style Guidelines—for example, it doesn't use i.e. or e.g., and it avoids I and we (first-person pronouns).
• This PR uses semantic line breaks
  of 80 characters or fewer.

[guidezpl]

Seeking feedback from reviewers. Initial thoughts:

• is it possible to add a test to check this for each file type?
• which file types don't need to be formatted
  • .svg
  • ...?