Add platform2 fork BUG=b/465833194 TEST=init and sync Change-Id: I67cfcc6acdf1f21c9a26fb4eb42e2681405cd20f Reviewed-on: https://cos-review.googlesource.com/c/cos/manifest/+/120647 Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com> Reviewed-by: He Gao <hegao@google.com>