[fix][coding] Make decimal count pushdown.

Author: nokiaMS

coding/src/main/java/io/dingodb/expr/coding/ExprCoder.java

@@ -374,16 +374,10 @@ public CodingFlag visitUnaryAggExpr(@NonNull UnaryAggExpr expr, @NonNull OutputS
             if (typeCode != null && index instanceof Integer) {
                 switch (expr.getOp().getName()) {
                     case CountAgg.NAME:
-                        if ( typeCode == 6) {  //Dont support decimal type now.
-                            return null;
-                        }
                         obj.write(AGG_COUNT | typeCode);
                         break;
                     case SumAgg.NAME:
                     case Sum0Agg.NAME:
-                        if ( typeCode == 6) {  //Dont support decimal type now.
-                            return null;
-                        }
                         obj.write(AGG_SUM | typeCode);
                         break;
                     case MaxAgg.NAME: