chore(ci): verify autorelease release PR content has changes (#234)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/b8d998b8-87b8-4f2e-b147-1d34fd8a86f9/targets

- [ ] To automatically regenerate this PR, check this box.

Source-Link: googleapis/synthtool@da29da3

.github/workflows/auto-release.yaml

@@ -21,6 +21,24 @@ jobs:
             return;
           }
 
+          // only approve PRs with pom.xml and versions.txt changes
+          const filesPromise = github.pulls.listFiles.endpoint({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            pull_number: context.payload.pull_request.number,
+          });
+          const changed_files = await github.paginate(filesPromise)
+
+          if ( changed_files.length < 1 ) {
+            console.log( "Not proceeding since PR is empty!" )
+            return;
+          }
+
+          if ( !changed_files.some(v => v.filename.includes("pom")) || !changed_files.some(v => v.filename.includes("versions.txt")) ) {
+            console.log( "PR file changes do not have pom.xml or versions.txt -- something is wrong. PTAL!" )
+            return;
+          }
+
           // trigger auto-release when
           // 1) it is a SNAPSHOT release (auto-generated post regular release)
           // 2) there are dependency updates only

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-container.git",
-        "sha": "3f133e5f02a215cbb927a6bac07725d30c18f714"
+        "sha": "f30bbbc904eee437320cfca05bafb8d83427e81e"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "95dbe1bee3c7f7e52ddb24a54c37080620e0d1a2"
+        "sha": "da29da32b3a988457b49ae290112b74f14b713cc"
       }
     }
   ],