Fix memory corruption in LayerRenderer::copyLayer

The pixel store pack alignment was not set for the source texture,
causing a write to occur outside of the destination bitmap's
bounds.

Change-Id: Iaa5767acf7b5943fbc2765c3810a142f06b1a796
diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index f81640b..5a8f2b7 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -400,6 +400,8 @@
         caches.activeTexture(0);
         glBindTexture(GL_TEXTURE_2D, texture);
 
+        glPixelStorei(GL_PACK_ALIGNMENT, bitmap->bytesPerPixel());
+
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);