Generalize KA check logic
Generalize KA check logic

Since the logic is for chunked encoding, we should be able to check the
availability instead of protocol names. This enables us to not maintain the
protocol list here that don't use chunked encoding.

SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,duke8253/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,pbchou/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,pbchou/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,vmamidi/trafficserver,vmamidi/trafficserver,duke8253/trafficserver,duke8253/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,duke8253/trafficserver,bryancall/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,duke8253/trafficserver,vmamidi/trafficserver