[test env] s/label/tags

Change-Id: I7d79c41a339586ed7e76cfa4c39a4d3d25fd6948
diff --git a/fuchsia/BUILD.gn b/fuchsia/BUILD.gn
index db309d6..aadd9fa 100644
--- a/fuchsia/BUILD.gn
+++ b/fuchsia/BUILD.gn
@@ -50,7 +50,7 @@
 foreach(env, magma_hardware_envs) {
   labeled_env = {
     forward_variables_from(env, "*")
-    label = "vulkan-cts"
+    tags = ["vulkan-cts"]
   }
   labeled_magma_hardware_envs += [ labeled_env ]
 }