Is the brick-concrete connection the 'weakest link' in brick made buildings? When an earthquake strikes,do buildings made of bricks and concrete break mostly on concrete-brick connection spots?If Yes does the brick on the picture prevents this from occuring?

 A: Brick structures fail in tension at the brick-to-mortar interface. The older the brick building is, the weaker becomes that interface, and 100 year old brick buildings are mostly held together by gravity. Earthquakes cause old brick buildings to easily collapse into low mounds of loose bricks, crushing the contents of the building.
The tongue-and-groove feature you propose makes the strength of the joint dependent on the tensile strength of the brick, which will fail readily when subjected to a suddenly-applied shock load.
The most common way to reinforce brick buildings is to use hollow bricks through which steel reinforcing rods have been threaded. The hollow spaces are then backfilled with cement to trap the steel in place.  The steel takes the tension loads and prevents the structure from being shaken into rubble, and keeps the building from collapsing completely under a shock load.
A: As far as I know, yes, brick-concrete connection is the weakest link. The connection would break if torque about the interface surpasses the the limit to which the interface is designed/expected to bear the torque.
The above design provied a counter torque about the interface due to normal force from the inclines at the interface(upto the limit that the inclines don't break). This prevents the interface from being a weak-link.
