material: fix implicit conflicts with master

Runtime/material/ink_well.cs

                 onTapDown: enabled ? (GestureTapDownCallback) this._handleTapDown : null,
                 onTap: enabled ? (GestureTapCallback) (() => this._handleTap(context)) : null,
                 onTapCancel: enabled ? (GestureTapCancelCallback) this._handleTapCancel : null,
-                onDoubleTap: this.widget.onDoubleTap != null ? (GestureDoubleTapCallback) this._handleDoubleTap : null,
+                onDoubleTap: this.widget.onDoubleTap != null ? (GestureDoubleTapCallback) (details => this._handleDoubleTap()) : null,
                 onLongPress: this.widget.onLongPress != null
                     ? (GestureLongPressCallback) (() => this._handleLongPress(context))
                     : null,

Runtime/material/material.cs

                 case MaterialType.card:
                 case MaterialType.button:
                     return new RoundedRectangleBorder(
-                        borderRadius: this.widget.borderRadius ?? MaterialUtils.kMaterialEdges[this.widget.type]);
+                        borderRadius: this.widget.borderRadius ?? MaterialConstantsUtils.kMaterialEdges[this.widget.type]);
                 case MaterialType.circle:
                     return new CircleBorder();
             }

Runtime/material/utils.cs

         public static readonly TimeSpan kThemeAnimationDuration = new TimeSpan(0, 0, 0, 0, 200);
     }
 
-    public static class MaterialUtils {
+    public static class MaterialConstantsUtils {
         public static readonly Dictionary<MaterialType, BorderRadius> kMaterialEdges =
             new Dictionary<MaterialType, BorderRadius> {
                 {MaterialType.canvas, null},

Samples/UIWidgetSample/MaterialCanvas.cs

                     child: new Center(
                         child: new MaterialButton(
                             color: Colors.blue,
-                            //splashColor: new Color(0xFFFF0011),
-                            //highlightColor: new Color(0x88FF0011),
+                            splashColor: new Color(0xFFFF0011),
+                            highlightColor: new Color(0x88FF0011),
                             onPressed: () => { Debug.Log("pressed here");}
                         )
                     )