成员的完整列表，这些成员属于 com.hyphenate.chat.EMCallSession.ConnectType,包括所有继承而来的类成员

DIRECT (定义于 com.hyphenate.chat.EMCallSession.ConnectType)	com.hyphenate.chat.EMCallSession.ConnectType
NONE (定义于 com.hyphenate.chat.EMCallSession.ConnectType)	com.hyphenate.chat.EMCallSession.ConnectType
RELAY (定义于 com.hyphenate.chat.EMCallSession.ConnectType)	com.hyphenate.chat.EMCallSession.ConnectType