SystemUI: Fix task manager title not change with language issue

When system language changes, task manager title and kill all button
name do not update.

Set task manager title and kill all button name when refresh task manager
view to ensure they change with system language. Rename task manager tile
to meet multi language requirement.

CRs-Fixed: 741079

Change-Id: Ic247c2a70cd63ccb87fd2f3bea05196e28060857