Why do you think your bricks are hollow ? If they are they are not suitable for expanding bolts anyway. I was thinking of the distance between holes in the joist hangers you have chosen . If you have the packet the bolts came in it should give the minimum edge distance and spacing between bolts. I avoided drilling into my half brick thick garage wall but I had block piers.
The bricks are perforated or engineering bricks meaning that there are three big holes in the middle. They may be full of mortar but might not be. I've researched a lot and this seems the safest solution .....