Ender Dragon dragon phase behaviors are broken after 19w08b

The different dragon phases (DragonPhase:0 through DragonPhase:10) of the Ender Dragon were broken by the fixes of MC-87942 and MC-91858. Previously, the Ender Dragon would freely fly around the arena with changing vertical heights. Due to the fix of the aforementioned two bugs, the Ender Dragon dragon phases have been broken, resulting in it getting stuck flying back and forth between two points in an oval-shape.

Expected Behavior: The ender dragon freely and fluently flies around the arena with changes in vertical height

Observed Behavior: The ender dragon frequently gets stuck going back and forth between two points, rather than fluently flying around the arena.

Relates to MC-271336