deps: update dependency com.google.protobuf:protobuf-java-util to v3.12.4 (#211)

* deps: update dependency com.google.protobuf:protobuf-java-util to v3.12.4

* chore: fix sample snippet tags

Co-authored-by: Jeff Ching <chingor@google.com>

Author: renovate-bot

samples/install-without-bom/pom.xml

@@ -23,22 +23,22 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
 
-  <!-- {x-version-update-start:google-cloud-monitoring:released} -->
   <dependencies>
+    <!-- {x-version-update-start:google-cloud-monitoring:released} -->
     <!-- [START monitoring_install_without_bom] -->
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-monitoring</artifactId>
       <version>1.100.2-SNAPSHOT</version>
     </dependency>
     <!-- [END monitoring_install_without_bom] -->
+    <!-- {x-version-update-end} -->
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java-util</artifactId>
-      <version>3.12.2</version>
+      <version>3.12.4</version>
     </dependency>
   </dependencies>
-  <!-- {x-version-update-end} -->
 
   <!-- compile and run all snippet tests -->
   <build>

samples/snapshot/pom.xml

@@ -33,7 +33,7 @@
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java-util</artifactId>
-      <version>3.12.2</version>
+      <version>3.12.4</version>
     </dependency>
 
     <dependency>

samples/snippets/pom.xml

@@ -42,11 +42,11 @@
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-monitoring</artifactId>
     </dependency>
-    <!-- [END monitoring_install_with_bom] -->
+    <!-- [START_EXCLUDE] -->
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java-util</artifactId>
-      <version>3.12.2</version>
+      <version>3.12.4</version>
     </dependency>
     <dependency>
       <groupId>junit</groupId>
@@ -60,5 +60,7 @@
       <version>1.0.1</version>
       <scope>test</scope>
     </dependency>
+    <!-- [END_EXCLUDE] -->
   </dependencies>
+  <!-- [END monitoring_install_with_bom] -->
 </project>