Polish "Align with breaking API changes in RedisCacheManager"

Closes gh-9734

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/RedisCacheConfiguration.java

@@ -57,7 +57,6 @@ class RedisCacheConfiguration {
 
 	@Bean
 	public RedisCacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
-
 		RedisCacheManagerBuilder builder = RedisCacheManager.builder(redisConnectionFactory);
 		List<String> cacheNames = this.cacheProperties.getCacheNames();
 		if (!cacheNames.isEmpty()) {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/cache/CacheAutoConfigurationTests.java

@@ -283,9 +283,9 @@ public class CacheAutoConfigurationTests {
 					RedisCacheManager cacheManager = validateCacheManager(context,
 							RedisCacheManager.class);
 					assertThat(cacheManager.getCacheNames()).isEmpty();
-					org.springframework.data.redis.cache.RedisCacheConfiguration configuration = (org.springframework.data.redis.cache.RedisCacheConfiguration) new DirectFieldAccessor(
+					assertThat(((org.springframework.data.redis.cache.RedisCacheConfiguration)
-							cacheManager).getPropertyValue("defaultCacheConfig");
+							new DirectFieldAccessor(cacheManager).getPropertyValue(
-					assertThat(configuration.usePrefix()).isTrue();
+									"defaultCacheConfig")).usePrefix()).isTrue();
 				});
 	}