chore: start tracking obsolete files (#522)

Author: yoshi-automation

packages/google-cloud-ndb/synth.metadata

@@ -4,15 +4,50 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/python-ndb.git",
-        "sha": "9ccbdd23448dcb401b111f03e951fa89ae65174f"
+        "sha": "521545c42451472bb14419bd1e2548eb3aff6976"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "bfcdbe0da977b2de6c1c0471bb6dc2f1e13bf669"
+        "sha": "80f46100c047bc47efe0025ee537dc8ee413ad04"
       }
     }
+  ],
+  "generatedFiles": [
+    ".kokoro/build.sh",
+    ".kokoro/continuous/common.cfg",
+    ".kokoro/continuous/continuous.cfg",
+    ".kokoro/docker/docs/Dockerfile",
+    ".kokoro/docker/docs/fetch_gpg_keys.sh",
+    ".kokoro/docs/common.cfg",
+    ".kokoro/docs/docs-presubmit.cfg",
+    ".kokoro/docs/docs.cfg",
+    ".kokoro/presubmit/common.cfg",
+    ".kokoro/presubmit/presubmit.cfg",
+    ".kokoro/publish-docs.sh",
+    ".kokoro/release.sh",
+    ".kokoro/release/common.cfg",
+    ".kokoro/release/release.cfg",
+    ".kokoro/samples/lint/common.cfg",
+    ".kokoro/samples/lint/continuous.cfg",
+    ".kokoro/samples/lint/periodic.cfg",
+    ".kokoro/samples/lint/presubmit.cfg",
+    ".kokoro/samples/python3.6/common.cfg",
+    ".kokoro/samples/python3.6/continuous.cfg",
+    ".kokoro/samples/python3.6/periodic.cfg",
+    ".kokoro/samples/python3.6/presubmit.cfg",
+    ".kokoro/samples/python3.7/common.cfg",
+    ".kokoro/samples/python3.7/continuous.cfg",
+    ".kokoro/samples/python3.7/periodic.cfg",
+    ".kokoro/samples/python3.7/presubmit.cfg",
+    ".kokoro/samples/python3.8/common.cfg",
+    ".kokoro/samples/python3.8/continuous.cfg",
+    ".kokoro/samples/python3.8/periodic.cfg",
+    ".kokoro/samples/python3.8/presubmit.cfg",
+    ".kokoro/test-samples.sh",
+    ".kokoro/trampoline.sh",
+    ".kokoro/trampoline_v2.sh"
   ]
 }