Make sure Redis cache prefix includes cache name

This commit maps 'spring.cache.redis.key-prefix' to the new
'prefixCacheNameWith' method introduced in Spring Data Neumann. This
makes sure that the configured prefix includes the cache name.

Closes gh-16676

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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -85,7 +85,7 @@ class RedisCacheConfiguration {
 			config = config.entryTtl(redisProperties.getTimeToLive());
 		}
 		if (redisProperties.getKeyPrefix() != null) {
-			config = config.prefixKeysWith(redisProperties.getKeyPrefix());
+			config = config.prefixCacheNameWith(redisProperties.getKeyPrefix());
 		}
 		if (!redisProperties.isCacheNullValues()) {
 			config = config.disableCachingNullValues();

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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -252,7 +252,7 @@ class CacheAutoConfigurationTests extends AbstractCacheAutoConfigurationTests {
 					RedisCacheConfiguration redisCacheConfiguration = getDefaultRedisCacheConfiguration(cacheManager);
 					assertThat(redisCacheConfiguration.getTtl()).isEqualTo(java.time.Duration.ofSeconds(15));
 					assertThat(redisCacheConfiguration.getAllowCacheNullValues()).isFalse();
-					assertThat(redisCacheConfiguration.getKeyPrefixFor("keyName")).isEqualTo("prefix");
+					assertThat(redisCacheConfiguration.getKeyPrefixFor("MyCache")).isEqualTo("prefixMyCache::");
 					assertThat(redisCacheConfiguration.usePrefix()).isTrue();
 				});
 	}