[dart][flutter][owners] Update owners file.

Add Alex and David to the in-tree OWNERS file.

Change-Id: I21802a475439749091cd89be4a7190841a9724b7
Reviewed-on: https://fuchsia-review.googlesource.com/c/topaz/+/587604
Fuchsia-Auto-Submit: Darren Chan <chandarren@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Reviewed-by: Chase Latta <chaselatta@google.com>
diff --git a/src/dart/OWNERS b/src/dart/OWNERS
index ac64fc4..43b609e 100644
--- a/src/dart/OWNERS
+++ b/src/dart/OWNERS
@@ -1,6 +1,8 @@
 # Flutter on fuchsia team members.
+akbiggs@google.com
 chandarren@google.com
 chaselatta@google.com
+dworsham@google.com
 jasoncampbell@google.com
 naudzghebre@google.com