Cracked and mossy stone brick infested blocks/monster eggs do not generate in strongholds

Relates to MC-140117 and MC-140118

As all three types of stone bricks generate in strongholds, one would expect all three infested variants of these blocks to also generate. However, this is not the case, as only regular stone brick monster eggs will generate and the other two must be created by factors outside of world generation.

To test:

• Locate stronghold
• /fill coordinateset1 coordinateset2 minecraft:red_stained_glass replace minecraft:stone_bricks
• /fill coordinateset1 coordinateset2 minecraft:green_stained_glass replace minecraft:cracked_stone_bricks
• /fill coordinateset1 coordinateset2 minecraft:blue_stained_glass replace minecraft:mossy_stone_bricks
• Note that the only surviving brick blocks in the radius are regular