chore: update libraries-bom to 4.2.0 (googleapis#88)

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Author: yoshi-automation

java-resourcemanager/README.md

@@ -20,7 +20,7 @@ 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>4.1.1</version>
+      <version>4.2.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>

java-resourcemanager/synth.metadata

@@ -1,5 +1,5 @@
 {
-  "updateTime": "2020-02-24T23:03:09.088925Z",
+  "updateTime": "2020-02-28T20:16:28.202014Z",
   "sources": [
     {
       "template": {