Fix Date32 json serialization for column store (#8848)

Author: fexolm

ydb/core/viewer/viewer_query.h

@@ -366,7 +366,7 @@ class TJsonQuery : public TViewerPipeClient {
             case NYdb::EPrimitiveType::Interval:
                 return TStringBuilder() << valueParser.GetInterval();
             case NYdb::EPrimitiveType::Date32:
-                return valueParser.GetInt32();
+                return valueParser.GetDate32();
             case NYdb::EPrimitiveType::Datetime64:
                 return valueParser.GetDatetime64();
             case NYdb::EPrimitiveType::Timestamp64: