chore: regenerate README versions (#183)

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README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>5.5.0</version>
+      <version>5.7.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-monitoring.git",
-        "sha": "568a61ae80726466b40680b4f99925550fc09bf7"
+        "sha": "30e64cab3aa0d5d1ed7f2277122dc4f6930f07cd"
       }
     },
     {