Replace nonexistent mock assert methods with real ones

Methods like assert_not_called, assert_called_once, assert_called do
not exist, they generated on the fly (dummy) and don't assert anything.
This patch replaces each of nonexistent method calls with real.

Change-Id: I12ac093b81a7a90b9b3771678ea2cc3c2a40c876
Closes-Bug: #1272428
Merge "Replace nonexistent mock assert methods with real ones"