chore: add synth config and repo metadata (#340)

.repo-metadata.json

@@ -0,0 +1,10 @@
+{
+  "name": "google-oauth-client",
+  "name_pretty": "Google OAuth Java Client",
+  "client_documentation": "oauths://googleapis.dev/java/google-oauth-client/latest/",
+  "release_level": "ga",
+  "language": "java",
+  "repo": "googleapis/google-oauth-java-client",
+  "repo_short": "google-oauth-java-client",
+  "distribution_name": "google-oauth-java-client"
+}

synth.py

@@ -0,0 +1,28 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""This script is used to synthesize generated parts of this library."""
+import synthtool as s
+import synthtool.gcp as gcp
+import logging
+
+logging.basicConfig(level=logging.DEBUG)
+common_templates = gcp.CommonTemplates()
+templates = common_templates.java_library()
+s.copy(templates, excludes=[
+    "README.md",
+    "java.header",
+    "checkstyle.xml",
+    "renovate.json",
+    "license-checks.xml",
+])