Fix Javadoc of KafkaConsumer (#6155)

The Javadoc is using Properties.put which should never be used because it allows putting non-strings into a Properties object which is designed to only handle strings.
Two other minor fixes so the examples actually work

clients/src/main/java/org/apache/kafka/clients/consumer/KafkaConsumer.java

@@ -201,12 +201,12 @@ import java.util.regex.Pattern;
  * <p>
  * <pre>
  *     Properties props = new Properties();
- *     props.put(&quot;bootstrap.servers&quot;, &quot;localhost:9092&quot;);
- *     props.put(&quot;group.id&quot;, &quot;test&quot;);
- *     props.put(&quot;enable.auto.commit&quot;, &quot;true&quot;);
- *     props.put(&quot;auto.commit.interval.ms&quot;, &quot;1000&quot;);
- *     props.put(&quot;key.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
- *     props.put(&quot;value.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
+ *     props.setProperty(&quot;bootstrap.servers&quot;, &quot;localhost:9092&quot;);
+ *     props.setProperty(&quot;group.id&quot;, &quot;test&quot;);
+ *     props.setProperty(&quot;enable.auto.commit&quot;, &quot;true&quot;);
+ *     props.setProperty(&quot;auto.commit.interval.ms&quot;, &quot;1000&quot;);
+ *     props.setProperty(&quot;key.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
+ *     props.setProperty(&quot;value.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
  *     KafkaConsumer&lt;String, String&gt; consumer = new KafkaConsumer&lt;&gt;(props);
  *     consumer.subscribe(Arrays.asList(&quot;foo&quot;, &quot;bar&quot;));
  *     while (true) {
@@ -239,17 +239,17 @@ import java.util.regex.Pattern;
  * <p>
  * <pre>
  *     Properties props = new Properties();
- *     props.put(&quot;bootstrap.servers&quot;, &quot;localhost:9092&quot;);
- *     props.put(&quot;group.id&quot;, &quot;test&quot;);
- *     props.put(&quot;enable.auto.commit&quot;, &quot;false&quot;);
- *     props.put(&quot;key.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
- *     props.put(&quot;value.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
+ *     props.setProperty(&quot;bootstrap.servers&quot;, &quot;localhost:9092&quot;);
+ *     props.setProperty(&quot;group.id&quot;, &quot;test&quot;);
+ *     props.setProperty(&quot;enable.auto.commit&quot;, &quot;false&quot;);
+ *     props.setProperty(&quot;key.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
+ *     props.setProperty(&quot;value.deserializer&quot;, &quot;org.apache.kafka.common.serialization.StringDeserializer&quot;);
  *     KafkaConsumer&lt;String, String&gt; consumer = new KafkaConsumer&lt;&gt;(props);
  *     consumer.subscribe(Arrays.asList(&quot;foo&quot;, &quot;bar&quot;));
  *     final int minBatchSize = 200;
  *     List&lt;ConsumerRecord&lt;String, String&gt;&gt; buffer = new ArrayList&lt;&gt;();
  *     while (true) {
- *         ConsumerRecords&lt;String, String&gt; records = consumer.poll(Duration.ofMillis(100);
+ *         ConsumerRecords&lt;String, String&gt; records = consumer.poll(Duration.ofMillis(100));
  *         for (ConsumerRecord&lt;String, String&gt; record : records) {
  *             buffer.add(record);
  *         }
@@ -470,6 +470,10 @@ import java.util.regex.Pattern;
  *     private final AtomicBoolean closed = new AtomicBoolean(false);
  *     private final KafkaConsumer consumer;
  *
+ *     public KafkaConsumerRunner(KafkaConsumer consumer) {
+ *       this.consumer = consumer;
+ *     }
+ *
  *     public void run() {
  *         try {
  *             consumer.subscribe(Arrays.asList("topic"));