DownloadProvider: Creates parent directories before creates file

Change-Id: I4b61c1aeb8054397fa2a2f162b068e683c7e9635
DownloadProvider: Properly open images

Open images with content://media/ instead of
content://downloads/ URI.

This allows images to be shared directly after opening them with the
DownloadManager.

Change-Id: I3648b1c563acaa80b28a230bdb43ead3476cf3e7
Merge changes I3648b1c5,I4b61c1ae into kitkat

* changes:
  DownloadProvider: Properly open images
  DownloadProvider: Creates parent directories before creates file