Prepare for Atmosphere Javascript 2.0 (#12241)

Atmosphere 2.0 has changed enableProtocol to default to true.
Reopening a connection in Atmosphere 2.0 is signalled through an onReopen event (not present at all in Atmosphere 1.0.x)

Change-Id: I6013a83a0239b6ab7535631120e442ece2d4481d