Add assistant_audiobox group

Add assistant_audiobox group to support Assistant audio tests that have
be to run inside audiobox.

BUG=b:240215093
TEST=fast_build.sh -T

Change-Id: Ia0c75fa1c6b6e208d99a5a19447446f7a040f28b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tast/+/3829464
Commit-Queue: Jonathan Fan <jonfan@chromium.org>
Tested-by: Jonathan Fan <jonfan@chromium.org>
Reviewed-by: Kyle Shimabukuro <kyleshima@chromium.org>
Reviewed-by: Yuki Awano <yawano@google.com>
Reviewed-by: Terry Yan <yichiyan@google.com>
Auto-Submit: Jonathan Fan <jonfan@chromium.org>
diff --git a/src/chromiumos/tast/internal/testing/attr.go b/src/chromiumos/tast/internal/testing/attr.go
index 09d39db..49d57cd 100644
--- a/src/chromiumos/tast/internal/testing/attr.go
+++ b/src/chromiumos/tast/internal/testing/attr.go
@@ -814,6 +814,11 @@
 			},
 		},
 	},
+	{
+		Name:     "assistant_audiobox",
+		Contacts: []string{"chromeos-sw-engprod@google.com", "assistive-eng@google.com"},
+		Desc:     `A group of Assistant tests that have to be run in audiobox.`,
+	},
 }
 
 // validGroupMap is the name-keyed map of validGroups.