Multipart upload file to google drive API #257

    let documents = knownFolders.documents();
    let folder = documents.getFolder("testFolder");
    let file = folder.getFile(("test") + ".json");

    var xxx = { "thing": "cat", "age": "19" };
    var jsonFile = JSON.stringify(xxx);

    file.writeText(jsonFile)
        .then(result => {

            var bghttp = require("nativescript-background-http");
            var session = bghttp.session("file-upload");

            var request = {
                url: "https://www.googleapis.com/upload/drive/v3/files?uploadType=multipart",
                method: "POST",
                headers: {
                    "Content-Type": "multipart/related",
                    "Authorization": `Bearer ${this.token.accessToken}`,
                },
                utf8: true
            };

            var params = [
                { name: "test", value: "I need to send metadata to the file I don't know how" },
                { name: "test", filename: file.path, mimeType: "application/json" }
            ];
            var task = session.multipartUpload(params, request);