build: add generated-files bot config (#45)

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Source-Link: googleapis/synthtool@e6f3d54
Source-Link: googleapis/synthtool@04573fd

packages/google-api-servicemanagement/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-service-management.git",
-        "sha": "13f1d7c5eedae569b7cd09e852d304d5540dd49a"
+        "sha": "35a796f54a272527f788d79fc6f858822e95e32f"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "c6706ee5d693e9ae5967614170732646590d8374"
+        "sha": "e6f3d54be015a394b6ab5a25903ec09062a2b424"
       }
     }
   ],