docs(auth): update setSettings() inline documentation

[creativecreatorormaybenot]

Description

Fixes the FirebaseAuth.setSettings docs, which @russellwheatley forgot to update in #6367. That is, the docs were missing documentation of the newly added parameters.

Additionally, I correctly the spelling of "Android" and adjusted the formatting of the different paragraphs to be consistent.

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]).
This will ensure a smooth and quick review process. Updating the pubspec.yaml and changelogs is not required.

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (melos run analyze) does not report any problems on my PR.
• I read and followed the Flutter Style Guide.
• I signed the CLA.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

• No, this is not a breaking change.