Call setShader after setLocalMatrix.

After updating a Shader's Matrix, set the Shader on the Paint again,
so it will take effect.

BUG:14315916
Change-Id: Ibf732f7f417d2a52500fabf4d660be7fcfb59f43

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

@@ -60,6 +60,7 @@ public class Sweep extends GraphicsActivity {
 
             mMatrix.setRotate(mRotate, x, y);
             mShader.setLocalMatrix(mMatrix);
+            mPaint.setShader(mShader);
             mRotate += 3;
             if (mRotate >= 360) {
                 mRotate = 0;

samples/devbytes/graphics/FoldingLayout/src/com/example/android/foldinglayout/FoldingLayout.java

@@ -477,6 +477,7 @@ public class FoldingLayout extends ViewGroup {
             mShadowGradientMatrix.setScale(1, mFoldDrawHeight);
             mShadowLinearGradient.setLocalMatrix(mShadowGradientMatrix);
         }
+        mGradientShadow.setShader(mShadowLinearGradient);
 
         mGradientShadow.setAlpha(alpha);
     }