Get correct density info when using resource URIs in ImageView

Before, when an android.resource URI was passed to
ImageView.setImageURI(), it was loaded through an InputStream.
This didn't get the density information correctly.

Instead, we use Resources to load the Drawable, which fixes
the denisty problem.

Change-Id: Ie8427ea04da43f414b49014d012671fc0aa27a30