Add generates_api to Auto Factory too

We're going to play it safe, since the third_party definition of Auto Factory seems to have it too.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=149534930

java/google/registry/repositories.bzl

@@ -710,6 +710,7 @@ def com_google_auto_factory():
           # TODO(jart): https://github.com/bazelbuild/bazel/issues/2286
           # "    output_licenses = [\"unencumbered\"],",
           "    processor_class = \"com.google.auto.factory.processor.AutoFactoryProcessor\",",
+          "    generates_api = 1,",
           "    tags = [\"annotation=com.google.auto.factory.AutoFactory;genclass=${package}.${outerclasses}@{className|${classname}Factory}\"],",
           "    deps = [\":processor\"],",
           ")",