Fix time-dynamic tracks
Fix time-dynamic tracks

likangning93/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,CesiumGS/cesium,likangning93/cesium,AnalyticalGraphicsInc/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium