[fuchsia_modular_testing] Fix issues in downstream dependencies with strict-deps

The previous change accidentally modified "fuchsia_modular", not "fuchsia_modular_testing"

Bug: b/153024243
Change-Id: I96a638c50da16f98a29fc2dae40b6b94782d68fc
Reviewed-on: https://fuchsia-review.googlesource.com/c/topaz/+/377920
Reviewed-by: Casey Borders <casbor@google.com>
Commit-Queue: Jerry Belton <jcecil@google.com>
diff --git a/public/dart/fuchsia_modular_testing/BUILD.gn b/public/dart/fuchsia_modular_testing/BUILD.gn
index 3d559a6..e7bc3e9 100644
--- a/public/dart/fuchsia_modular_testing/BUILD.gn
+++ b/public/dart/fuchsia_modular_testing/BUILD.gn
@@ -27,7 +27,7 @@
     "//sdk/fidl/fuchsia.modular.session",
     "//sdk/fidl/fuchsia.modular.testing",
     "//sdk/fidl/fuchsia.sys",
-    "//third_party/dart-pkg/pub/meta",
+    "//third_party/dart-pkg/pub/async",
     "//topaz/public/dart/fidl",
     "//topaz/public/dart/fuchsia_logger",
     "//topaz/public/dart/fuchsia_modular",