ProgressManager: Unify style of progress manager task descriptions

Change-Id: I6826e66f00f47997c644c24d1b20f4a1ea53a8a2
(cherry picked from commit 36d8ec4f4771ebeb9d923af35c473e11bae1fe29)
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>