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
DownloadProvider: Update copyright year

Change-Id: Ia3efa747daadeead622e25544b4ac1d9766bdd80
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_providers_DownloadProvider into kk44