fix: Apply Google Java Code Clarity suggestions (#1044)

* fix: Apply Google Java Code Clarity suggestions

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: Ben Creech <bpcreech@google.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: 3 people

Diff for: google-cloud-logging/clirr-ignored-differences.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<differences>
+  <difference>
+    <differenceType>3003</differenceType>
+    <className>com/google/cloud/logging/Instrumentation</className>
+  </difference>
+  <difference>
+    <differenceType>7009</differenceType>
+    <className>com/google/cloud/logging/Instrumentation</className>
+    <method>Instrumentation()</method>
+  </difference>
+</differences>

Diff for: google-cloud-logging/pom.xml

@@ -127,6 +127,11 @@
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava-testlib</artifactId>
+      <scope>test</scope>
+    </dependency>
 
     <dependency>
       <groupId>com.google.api.grpc</groupId>