Fixing a buildifier warning, helping with future imports. (#26036)

test/cpp/end2end/BUILD

@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-licenses(["notice"])
-
 load("//bazel:grpc_build_system.bzl", "grpc_cc_binary", "grpc_cc_library", "grpc_cc_test", "grpc_package")
 
+licenses(["notice"])
+
 grpc_package(
     name = "test/cpp/end2end",
     visibility = "public",