With the addition of admission priority for storage engine ticket acquisition, we should have flow control also use this priority to inform whether or not operations take flow control tickets as well.

This would replace explict calls to setShouldParticipateInFlowControl().

In making this change, we will need to evaluate the following:

• Should all operations that bypass flow control also be bypassing ticket acquisition using "kImmediate" admission priority?
• Should all operations that bypass ticket acquisition should also bypass flow control?

If both of these conditions are universally true, then it would simplify our admission system and bring these two mechanisms closer together in behavior.