remove unrecognized javadoc tag from matrix aggregation module

modules/aggs-matrix-stats/src/main/java/org/elasticsearch/search/aggregations/matrix/stats/MatrixStatsResults.java

@@ -31,8 +31,6 @@ import java.util.Map;
 /**
  * Descriptive stats gathered per shard. Coordinating node computes final pearson product coefficient
  * based on these descriptive stats
- *
- * @internal
  */
 class MatrixStatsResults implements Writeable {
     /** object holding results - computes results in place */

modules/aggs-matrix-stats/src/main/java/org/elasticsearch/search/aggregations/matrix/stats/RunningStats.java

@@ -34,8 +34,6 @@ import java.util.Map;
  * based on these descriptive stats. This single pass, parallel approach is based on:
  *
  * http://prod.sandia.gov/techlib/access-control.cgi/2008/086212.pdf
- *
- * @internal
  */
 public class RunningStats implements Writeable, Cloneable {
     /** count of observations (same number of observations per field) */