Set ActionMode title to the number of selected files

After change of orientation ActionMode is recreated without previously
set title. It needs to be updated in onCreateActionMode callback.

Change-Id: If5f36e8ad6d1b5cf04ed242611fd037969d73517
Avoid SystemUI crash due to NPE

BaseStatusBar.createNotificationViews() returns null
when it reports handleNotificationError(), leading to
a forced crash of the misbehaving app. However, it
should not add a null object of Notification.Entry
since it will also crash SystemUI (crashing at compare).

Change-Id: I86678c8024e931420b0fbab1f36b330e7e75d581