Updates Cesium_Air model to GLTF2.0
Updates Cesium_Air model to GLTF2.0

CesiumGS/cesium,YonatanKra/cesium,YonatanKra/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,CesiumGS/cesium,progsung/cesium,progsung/cesium,likangning93/cesium,CesiumGS/cesium,YonatanKra/cesium,AnalyticalGraphicsInc/cesium,CesiumGS/cesium,likangning93/cesium,likangning93/cesium,CesiumGS/cesium,likangning93/cesium,YonatanKra/cesium