[Autofill] Remove last ServerFieldType occurrences, finally

crrev.com/c/5135875 still missed the metrics files because I had done
$ git ls-file | xargs grep ServerFieldType
instead of using NUL as separator as in
$ git ls-files -z | xargs -0 grep ServerFieldType
or just
$ git grep -l ServerFieldType

Bug: 1511368
Change-Id: Ia33cd12ce02210f5b710bd5879165f544480fb63
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5136938
Commit-Queue: Christoph Schwering <schwering@google.com>
Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Dominic Battre <battre@chromium.org>
Reviewed-by: Jihad Hanna <jihadghanna@google.com>
Reviewed-by: Sun Yueru <yrsun@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1242729}