title: ColorDrawable placeholder not loading in glide
body: <p>Am I doing something wrong here? I want to load that gray as a placeholder however, it doesn't load. It seems to only happen if there was already another image set or loaded.</p>
  
  <pre><code>Glide.with(getContext())
      .load(url)
      .placeholder(new ColorDrawable(ContextCompat.getColor(getContext(), R.color.placeholder_gray)))
      .error(new ColorDrawable(ContextCompat.getColor(getContext(), R.color.placeholder_gray)))
      .dontAnimate()
      .into(new SimpleTarget&lt;GlideDrawable&gt;() {
        @Override
        public void onResourceReady(GlideDrawable resource, GlideAnimation&lt;? super GlideDrawable&gt; glideAnimation) {
          image.setImageDrawable(resource);
        }
  
        @Override
        public void onLoadFailed(Exception e, Drawable errorDrawable) {
          resetImageView();
        }
      });
  </code></pre>