[css-anchor-position] Fixed serialization of position-try
The shorthand serialized the position-try-order size and just omitted
the position-try-options value.
Bug: 350779990
Change-Id: I143903c6d53f832f91c121e9955e9f18daedbaf5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5673354
Reviewed-by: Morten Stenshorne mstensho@chromium.org
Commit-Queue: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1322785}