chore(java): ignore return code 28 in README autosynth job (#258)

This PR was generated using Autosynth. 🌈 Synth log will be available here: https://source.cloud.google.com/results/invocations/56f6b42a-a80d-49a4-8def-3f7c5f01609c/targets - [ ] To automatically regenerate this PR, check this box. Source-Link: googleapis/synthtool@7db8a6c

Author: yoshi-automation

.kokoro/readme.sh

@@ -28,9 +28,18 @@ echo "https://${GITHUB_TOKEN}:@github.com" >> ~/.git-credentials
 git config --global credential.helper 'store --file ~/.git-credentials'
 
 python3.6 -m pip install git+https://github.com/googleapis/synthtool.git#egg=gcp-synthtool
+
+set +e
 python3.6 -m autosynth.synth \
  --repository=googleapis/java-billing \
  --synth-file-name=.github/readme/synth.py \
  --metadata-path=.github/readme/synth.metadata \
  --pr-title="chore: regenerate README" \
- --branch-suffix="readme"
+ --branch-suffix="readme"
+
+# autosynth returns 28 to signal there are no changes
+RETURN_CODE=$?
+if [[ ${RETURN_CODE} -ne 0 && ${RETURN_CODE} -ne 28 ]]
+then
+ exit ${RETURN_CODE}
+fi

synth.metadata

@@ -4,7 +4,7 @@
  "git": {
  "name": ".",
  "remote": "https://github.com/googleapis/java-billing.git",
- "sha": "b6ffe7695a9595d857b19096e1d63820d20e5958"
+ "sha": "6b71670ab99f4194589df3222bfab6b5c20890c2"
  }
  },
  {
@@ -19,7 +19,7 @@
  "git": {
  "name": "synthtool",
  "remote": "https://github.com/googleapis/synthtool.git",
- "sha": "c7824ea48ff6d4d42dfae0849aec8a85acd90bd9"
+ "sha": "7db8a6c5ffb12a6e4c2f799c18f00f7f3d60e279"
  }
  }
  ],