Set default retry strategy

Author: Ajay Kannan

gcloud-java-core/src/main/java/com/google/gcloud/ServiceOptions.java

@@ -264,7 +264,8 @@ public B authCredentials(AuthCredentials authCredentials) {
 
     /**
      * Sets configuration parameters for request retries. If no configuration is set
-     * {@link RetryParams#noRetries()} is used.
+     * {@link RetryParams#defaultInstance()} is used. To disable retries, supply
+     * {@link RetryParams#noRetries()} here.
      *
      * @return the builder
      */
@@ -325,7 +326,7 @@ protected ServiceOptions(Class<? extends ServiceFactory<ServiceT, OptionsT>> ser
     authCredentials =
         builder.authCredentials != null ? builder.authCredentials : defaultAuthCredentials();
     authCredentialsState = authCredentials != null ? authCredentials.capture() : null;
-    retryParams = builder.retryParams;
+    retryParams = firstNonNull(builder.retryParams, RetryParams.defaultInstance());
     serviceFactory = firstNonNull(builder.serviceFactory,
         getFromServiceLoader(serviceFactoryClass, defaultServiceFactory()));
     serviceFactoryClassName = serviceFactory.getClass().getName();