成员的完整列表，这些成员属于 com.netease.lava.nertc.sdk.video.NERtcVideoConfig.NERtcDegradationPreference,包括所有继承而来的类成员

DEGRADATION_BALANCED	com.netease.lava.nertc.sdk.video.NERtcVideoConfig.NERtcDegradationPreference
DEGRADATION_DEFAULT	com.netease.lava.nertc.sdk.video.NERtcVideoConfig.NERtcDegradationPreference
DEGRADATION_MAINTAIN_FRAMERATE	com.netease.lava.nertc.sdk.video.NERtcVideoConfig.NERtcDegradationPreference
DEGRADATION_MAINTAIN_QUALITY	com.netease.lava.nertc.sdk.video.NERtcVideoConfig.NERtcDegradationPreference