Fix broken GN "all_dependent_configs".

BUILD.gn

@@ -288,7 +288,7 @@ angle_static_library("angle_common") {
   ]
   public_configs += [ ":angle_common_config" ]
   if (angle_has_build && use_fuzzing_engine) {
-    all_dependent_configs += [ ":angle_disable_pool_alloc" ]
+    all_dependent_configs = [ ":angle_disable_pool_alloc" ]
   }
 }