Enable redis password in Java worker (#3943)

* Support Java redis password

* Fix

* Refine

* Fix lint.

java/runtime/src/main/resources/ray.default.conf

@@ -64,6 +64,10 @@ ray {
     address: ""
     // If `redis.server` isn't provided, which port we should use to start redis server.
     head-port: 6379
+    // The password used to start the redis server on the head node.
+    head-password: ""
+    // The password used to connect to the redis server.
+    password:""
     // If `redis.server` isn't provided, how many Redis shards we should start in addition to the
     // primary Redis shard. The ports of these shards will be `head-port + 1`, `head-port + 2`, etc.
     shard-number: 1