Fix compatibility with Apache Kafka 0.10.1

Update KafkaProperties since  Apache Kafka `0.10.1` changed the type
for the `ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG` from the
`Long` to `Integer`.

Kafka includes the following conversion logic:

    case LONG:
        if (value instanceof Integer)
            return ((Integer) value).longValue();
        if (value instanceof Long)
            return (Long) value;
        else if (value instanceof String)
            return Long.parseLong(trimmed);

So we remain compatible with both `0.10.0` and `0.10.1`

Closes gh-7723

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/kafka/KafkaProperties.java

@@ -43,6 +43,7 @@ import org.springframework.util.CollectionUtils;
  *
  * @author Gary Russell
  * @author Stephane Nicoll
+ * @author Artem Bilan
  * @since 1.5.0
  */
 @ConfigurationProperties(prefix = "spring.kafka")
@@ -199,7 +200,7 @@ public class KafkaProperties {
 		 * Frequency in milliseconds that the consumer offsets are auto-committed to Kafka
 		 * if 'enable.auto.commit' true.
 		 */
-		private Long autoCommitInterval;
+		private Integer autoCommitInterval;
 
 		/**
 		 * What to do when there is no initial offset in Kafka or if the current offset
@@ -264,11 +265,11 @@ public class KafkaProperties {
 			return this.ssl;
 		}
 
-		public Long getAutoCommitInterval() {
+		public Integer getAutoCommitInterval() {
 			return this.autoCommitInterval;
 		}
 
-		public void setAutoCommitInterval(Long autoCommitInterval) {
+		public void setAutoCommitInterval(Integer autoCommitInterval) {
 			this.autoCommitInterval = autoCommitInterval;
 		}
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/kafka/KafkaAutoConfigurationTests.java

@@ -100,7 +100,7 @@ public class KafkaAutoConfigurationTests {
 		assertThat(configs.get(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG))
 				.isEqualTo(Boolean.FALSE);
 		assertThat(configs.get(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG))
-				.isEqualTo(123L);
+				.isEqualTo(123);
 		assertThat(configs.get(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG))
 				.isEqualTo("earliest");
 		assertThat(configs.get(ConsumerConfig.FETCH_MAX_WAIT_MS_CONFIG)).isEqualTo(456);