Remove common SampleCancelProc and SampleRenderProgressProc

    Re-using these callbacks caused issues on ARM Linux. Cancel callback
    appeared to be getting called twice.  Making new one for each Draw
    function call has alleviated this issue.

DotNETCore/Sample_Source/Images/DrawToBitmap/DrawToBitmap.cs

@@ -89,9 +89,6 @@ private static DrawParams ConstructDrawParams(Matrix matrix, Rect updateRect, bo
 
             parms.EnableBlackPointCompensation = blackPointCompensation;
 
-            parms.CancelProc = new SampleCancelProc();
-            parms.ProgressProc = new SampleRenderProgressProc();
-
             return parms;
         }
 
@@ -226,6 +223,8 @@ static void DrawToBitmapWithDrawParams(Page pg, DrawParams parms)
 
             using (Bitmap bitmap = new Bitmap(width, height))
             {
+                parms.CancelProc = new SampleCancelProc();
+                parms.ProgressProc = new SampleRenderProgressProc();
                 pg.DrawContents(bitmap, parms);
                 SaveBitmap(bitmap, "Bitmap");
             }
@@ -269,6 +268,8 @@ static void DrawToGraphicsWithDrawParams(Page pg, DrawParams parms)
 
             using (Bitmap bitmap = new Bitmap(width, height))
             {
+                parms.CancelProc = new SampleCancelProc();
+                parms.ProgressProc = new SampleRenderProgressProc();
                 pg.DrawContents(bitmap, parms);
                 SaveBitmap(bitmap, "Graphics");
             }