Creates parent directories before creates file

Change-Id: I124f7ce2b731b100e9572d7c5d95206e243ee316
Signed-off-by: Roger Chen <cxr514033970@gmail.com>
Remove download notification after preview

Removes download notification from the notification bar after
previewing it. There should be an additional check for download
shown in the notifications after completion to prevent from
situation when ContentObserver is unregistered and the onChange
is never called.

Change-Id: I0914a680f08eb96949b56e08719eb28d2e80ccc9