Default to no data value when processing statistics

In GridToPointConverter, default to the no data value when processing zonal statistics. This ensures the no data value of the output matches the input.

vortex-api/src/main/java/mil/army/usace/hec/vortex/geo/ZonalStatisticsCalculator.java

@@ -222,14 +222,14 @@ private ZonalStatistics computeZonalStatistics(String id, Integer[] mask, float[
 
         double sum = validValues.stream().mapToDouble(f -> f).sum();
         int count = validValues.size();
-        double average = Double.NaN;
-        double min = Double.NaN;
-        double max = Double.NaN;
-        double median = Double.NaN;
-        double firstQuartile = Double.NaN;
-        double thirdQuartile = Double.NaN;
-        float pctCellsGreaterThanZero = Float.NaN;
-        float pctCellsGreaterThanFirstQuartile = Float.NaN;
+        double average = noDataValue;
+        double min = noDataValue;
+        double max = noDataValue;
+        double median = noDataValue;
+        double firstQuartile = noDataValue;
+        double thirdQuartile = noDataValue;
+        double pctCellsGreaterThanZero = noDataValue;
+        double pctCellsGreaterThanFirstQuartile = noDataValue;
         int numCellsGreaterThanZero = 0;
         int numCellsGreaterThanFirstQuartile = 0;
 
@@ -245,7 +245,7 @@ private ZonalStatistics computeZonalStatistics(String id, Integer[] mask, float[
                 }
             }
 
-            pctCellsGreaterThanZero = (float) (100 * numCellsGreaterThanZero) / count;
+            pctCellsGreaterThanZero = (double) (100 * numCellsGreaterThanZero) / count;
 
         }
 
@@ -265,7 +265,7 @@ private ZonalStatistics computeZonalStatistics(String id, Integer[] mask, float[
                     numCellsGreaterThanFirstQuartile++;
                 }
             }
-            pctCellsGreaterThanFirstQuartile = (float) (100 * numCellsGreaterThanFirstQuartile) / count;
+            pctCellsGreaterThanFirstQuartile = (double) (100 * numCellsGreaterThanFirstQuartile) / count;
 
         }