Make HiveMetastoreConfig class public

Commit 2c572cb introduced the Java client APIs to fetch HMS integration
configuration. This patch makes the org.apache.kudu.client.HiveMetastoreConfig
class, which contains the Hive Metastore configuration of a Kudu cluster,
public. So that it can be accessed from outside package, e.g. org.apache.impala.

Change-Id: I6e7e9eaeba65512a2bcce6dc7f1202215f60266e
Reviewed-on: http://gerrit.cloudera.org:8080/13128
Reviewed-by: Todd Lipcon <[email protected]>
Reviewed-by: Alexey Serbin <[email protected]>
Tested-by: Andrew Wong <[email protected]>
Reviewed-by: Andrew Wong <[email protected]>

java/kudu-client/src/main/java/org/apache/kudu/client/HiveMetastoreConfig.java

@@ -25,7 +25,7 @@
  */
 @InterfaceAudience.LimitedPrivate("Impala")
 @InterfaceStability.Unstable
-class HiveMetastoreConfig {
+public class HiveMetastoreConfig {
   private final String hiveMetastoreUris;
   private final boolean hiveMetastoreSaslEnabled;
   private final String hiveMetastoreUuid;