Bug Fix with Sampler

src/main/java/org/opensearch/knn/quantization/sampler/ReservoirSampler.java

@@ -78,8 +78,7 @@ private int[] reservoirSampleIndices(final int numVectors, final int sampleSize)
                 indices[j] = i;
             }
         }
-        // If sorted indices are required, uncomment the following line
-        // Arrays.sort(indices);
+        Arrays.sort(indices);
         return indices;
     }
 }