ec2: homedir bug fixed in 24.1.4

This bug fix is due to be released in Quarterly:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=275896

While here, overwrite the doas stanza, which needs to correspond to
the user that we are creating.

MFC after: 5 days
Sponsored by: The FreeBSD Foundation
Pull Request: https://github.com/freebsd/freebsd-src/pull/1163

(cherry picked from commit 2039437c7655c9cd481c6c4ad92b6bc2a945dd14)