switch to a private constructor for filter element

app/src/main/java/net/pokeranalytics/android/model/realm/FilterElement.kt

@@ -9,7 +9,12 @@ import net.pokeranalytics.android.ui.view.rowrepresentable.FilterElementRow.*
 import java.util.*
 import kotlin.collections.ArrayList
 
-open class FilterElement(var filterName : String = "", var sectionName: String = "") : RealmObject() {
+open class FilterElement() : RealmObject() {
+
+    private constructor(filterName:String, sectionName:String) : this() {
+        this.filterName = filterName
+        this.sectionName = sectionName
+    }
 
     constructor(filterElementRows: ArrayList<FilterElementRow>) : this(filterElementRows.first().filterName, filterElementRows.first().filterSectionRow.name) {
         this.stringValues = when (QueryType.valueOf(this.filterName)) {
@@ -81,6 +86,9 @@ open class FilterElement(var filterName : String = "", var sectionName: String =
         }
     }
 
+    var filterName : String = ""
+    var sectionName : String = ""
+
     val queryType : QueryType
         get() = QueryType.valueOf(filterName)
             .apply {