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

QUALITY_BAD	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_DOWN	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_EXCELLENT	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_GOOD	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_POOR	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_UNKNOWN	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality
QUALITY_VBAD	com.netease.lava.nertc.sdk.NERtcConstants.NERtcLastmileQuality