Revert "Support alpha for SurfaceView"

Revert submission 19562144-surfaceview-alpha

Reason for revert: Presubmit breakage b/245651921
Reverted Changes:
I7510a3a6c:Add CTS for applying alpha for SurfaceView
Ibc14b18f1:Support alpha for SurfaceView

Change-Id: I498c98951a53e6bb1c1251dceb9d150311b07cc8
diff --git a/libs/hwui/SkiaCanvas.h b/libs/hwui/SkiaCanvas.h
index 51007c5..c6313f6 100644
--- a/libs/hwui/SkiaCanvas.h
+++ b/libs/hwui/SkiaCanvas.h
@@ -65,7 +65,7 @@
         LOG_ALWAYS_FATAL("SkiaCanvas does not support enableZ");
     }
 
-    virtual void punchHole(const SkRRect& rect, float alpha) override;
+    virtual void punchHole(const SkRRect& rect) override;
 
     virtual void setBitmap(const SkBitmap& bitmap) override;