[SPARK-8865] [STREAMING] FIX BUG: check key in kafka params

Author: guowei2 <guowei@growingio.com>

Closes #7254 from guowei2/spark-8865 and squashes the following commits:

48ca17a [guowei2] fix contains key

external/kafka/src/main/scala/org/apache/spark/streaming/kafka/KafkaCluster.scala

@@ -410,7 +410,7 @@ object KafkaCluster {
       }
 
       Seq("zookeeper.connect", "group.id").foreach { s =>
-        if (!props.contains(s)) {
+        if (!props.containsKey(s)) {
           props.setProperty(s, "")
         }
       }