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: I65c79923b7aef4c1113e572030c9c7f750b73df0
Clear notifications for Deleted items from Download list

Issue: Notifications for deleted items from the Download
list are not getting cleared and thus tapping on such
notifications causes crash (Illegal Argument Exception)

Fix: clear notifications for deleted items by adding them
in the stale list

Change-Id: I7a27d19fff994876eee07d4c4d63b2808cc516d3
CRs-Fixed: 536562
DownloadProvider: don't allow backups.

Change-Id: I5a07244d4bb7e11af4f5eb1a624fc20165248aab
Creates parent directories before creates file

Change-Id: I124f7ce2b731b100e9572d7c5d95206e243ee316
Signed-off-by: Roger Chen <cxr514033970@gmail.com>