[@container] Add parsing tests for comma separated queries
Also add a test that '@container {}' is not a valid rule.
Change-Id: Id8662623617a682d9408017db74c20ec362cc7ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6001964
Reviewed-by: Anders Hartvoll Ruud andruud@chromium.org
Commit-Queue: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1380338}