Update SampleAndroidShadows to use algorithm closer to Android OpenGL

src/effects/SkGaussianEdgeShader.cpp

Index: src/effects/SkGaussianEdgeShader.cpp
diff --git a/src/effects/SkGaussianEdgeShader.cpp b/src/effects/SkGaussianEdgeShader.cpp
index d73bfadbd77bead16a7c33f836186fd313a2bde1..19f92c84f53b1991da8f7281f43653cc8f86df3f 100644
--- a/src/effects/SkGaussianEdgeShader.cpp
+++ b/src/effects/SkGaussianEdgeShader.cpp
@@ -71,13 +71,13 @@ public:
             GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
 
             fragBuilder->codeAppendf("vec4 color = %s;", args.fInputColor);
-            fragBuilder->codeAppend("float radius = color.g*64.0;");
+            fragBuilder->codeAppend("float radius = color.r*1024.0 + color.g*64.0;");
             fragBuilder->codeAppend("float pad = color.b*64.0;");
 
             fragBuilder->codeAppendf("float factor = 1.0 - clamp((%s.z - pad)/radius, 0.0, 1.0);",
                                      fragBuilder->distanceVectorName());
             fragBuilder->codeAppend("factor = exp(-factor * factor * 4.0) - 0.018;");
-            fragBuilder->codeAppendf("%s = factor*vec4(0.0, 0.0, 0.0, color.r);", args.fOutputColor);
+            fragBuilder->codeAppendf("%s = factor*vec4(0.0, 0.0, 0.0, color.a);", args.fOutputColor);
         }
 
         static void GenKey(const GrProcessor& proc, const GrGLSLCaps&,