GH-3805: Introduce RedisLockRegistry.RedisLockType mode

Fixes https://github.com/spring-projects/spring-integration/issues/3805

The Redis Pub-Sub doesn't work in all the environment, therefore there has to
be a choice to use old busy-spin algorithm

* Change to select between spinLock method and pub-sub method
* Make spinLock as a default one to let the `RedisLockRegistry` work everywhere
* Fix javadoc, convention, lazy init
* Fix javadoc, convention
* Code clean up and docs for `RedisLockType` feature

**Cherry-pick to 5.5.x**

src/reference/asciidoc/redis.adoc

@@ -887,3 +887,12 @@ Starting with version 5.0, the `RedisLockRegistry` implements `ExpirableLockRegi
 
 String with version 5.5.6, the `RedisLockRegistry` is support automatically clean up cache for redisLocks in `RedisLockRegistry.locks` via `RedisLockRegistry.setCacheCapacity()`.
 See its JavaDocs for more information.
+
+String with version 5.5.13, the `RedisLockRegistry` exposes a `setRedisLockType(RedisLockType)` option to determine in which mode a Redis lock acquisition should happen:
+
+- `RedisLockType.SPIN_LOCK` - the lock is acquired by periodic loop (100ms) checking whether the lock can be acquired.
+Default.
+- `RedisLockType.PUB_SUB_LOCK` - The lock is acquired by redis pub-sub subscription.
+
+The pub-sub is preferred mode - less network chatter between client Redis server, and more performant - the lock is acquired immediately when subscription is notified about unlocking in the other process.
+However, the Redis does not support pub-sub in the Master/Replica connections (for example in AWS ElastiCache environment), therefore a busy-spin mode is chosen as a default to make the registry working in any environment.