title: Get rgba uint8[] from ARGB_8888 bitmap
body: <p>I have a bitmap and I am trying to get the the data to be an rgba byte array. I can do <code>bmp.getPixels</code> but this is not in rgba bytes. My end destination was to feed this to an HTML5 canvas which requires an 4 elements (r, g, b, a) per pixel. Is this possible?</p>
  
  <p>This is the code I am using to get my bmp:</p>
  
  <pre><code>Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Config.ARGB_8888);
  Canvas canvas = new Canvas(bitmap);
  view.draw(canvas);
  // can do bmp.getPixels here but it doesnt give RGBA :(
  </code></pre>
  
  <p>I tried this:</p>
  
  <pre><code>bmp.copyPixelsToBuffer(ByteBuffer.wrap(buffer));
  </code></pre>
  
  <p>but the contents of buffer is extremely weird, it doesnt look like rgba to me, it looks like this:</p>
  
  <pre><code>[ 54, 59, 64, -1, 54, 59, 64, -1,
  </code></pre>
  
  <p>Those <code>-1</code>s especially look weird.</p>