Don't hardcode 320x480 size in the FingerPaint API demo.

Change-Id: I4de9ce1e52dda68bf4c3ab7fbd9987ca6d5548a0

samples/ApiDemos/src/com/example/android/apis/graphics/FingerPaint.java

@@ -68,8 +68,6 @@ public class FingerPaint extends GraphicsActivity
         public MyView(Context c) {
             super(c);
 
-            mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
-            mCanvas = new Canvas(mBitmap);
             mPath = new Path();
             mBitmapPaint = new Paint(Paint.DITHER_FLAG);
         }
@@ -77,6 +75,8 @@ public class FingerPaint extends GraphicsActivity
         @Override
         protected void onSizeChanged(int w, int h, int oldw, int oldh) {
             super.onSizeChanged(w, h, oldw, oldh);
+            mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
+            mCanvas = new Canvas(mBitmap);
         }
 
         @Override