Are you allowed to remove those outcroppings? What's behind the brick? Any reason why you aren't considering a metal sleeve anchor made for masonry?

If it were my place, I'd take out the mortar around those outcroppings and ideally clean up and re-use the same brick to fill the space. Once the mortar was dry, I'd use metal sleeve anchors, at least 4", to bolt a mount to the wall, then hang the TV.

Alternatively, if modifying the brick isn't an option, I'd make spacer block[s] out of wood and bolt them to the wall with the aforementioned sleeve anchors or metal anchors and lag bolts. Countersink the bolt heads with a spade bit so it doesn't interfere with your mount. Then lag the tv mount to the spacer[s]. You'd want the thickness of your spacer to be the length of the outcropping, less the depth of your mounting bracket, plus half an inch or so for clearance. Looks to me like a couple pieces of 4x4, mounted vertically would do the trick.