If you are still experiencing this issue with the latest version of the ArcGIS Runtime SDK for Android 100.x, please reach out to Esri Support Services.
解决办法
Override GPFeatureRecordSetLayer.generateValueParams() to replace the one instance of spatialReference with sr as below:
public String generateValueParams() throws Exception {
return super.generateValueParams().replace("\"esriGeometryPoint\",\"spatialReference\":", "\"esriGeometryPoint\",\"sr\":");
}