Make sure notification is shown when playback is started via media
button intent.

Also make sure to properly remove it when music is stopped with screen
of (e.g. when playing via BT): As handlers only count non-sleep times,
we have to use the alarm manager in order to make sure the notification
is removed after 1 minute.

JIRA: CYAN-1067
Change-Id: I87a5328e5116d199e2f62119f5a76eca73a3ee4e
Merge "Make sure notification is shown when playback is started via media button intent." into cm-10.1