chore(gax): Update resize delta's getter to be package-private (#12886)

Co-authored-by: cloud-java-bot <cloud-java-bot@google.com>

Author: lqiu96

gapic-libraries-bom/pom.xml

@@ -1259,7 +1259,7 @@
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-spanner-bom</artifactId>
-        <version>6.116.0</version><!-- {x-version-update:google-cloud-spanner:current} -->
+        <version>6.116.1</version><!-- {x-version-update:google-cloud-spanner:current} -->
         <type>pom</type>
         <scope>import</scope>
       </dependency>

sdk-platform-java/gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/ChannelPoolSettings.java

@@ -110,7 +110,7 @@ public abstract class ChannelPoolSettings {
    * <p><b>Warning:</b> Higher values for resize delta may still result in performance degradation
    * during spikes due to rapid scaling.
    */
-  public abstract int getMaxResizeDelta();
+  abstract int getMaxResizeDelta();
 
   /**
    * The initial size of the channel pool.