function execDecode(buffer, charset) {
	return new Promise((resolve, reject) => {
		cordova.exec(
			(text) => {
				resolve(text);
			},
			(error) => {
				reject(error);
			},
			"System",
			"decode",
			[buffer, charset],
		);
	});
}
Decodes arrayBuffer to String according given encoding type
@param {ArrayBuffer} buffer
@param {string} charset
@returns {Promise<string>}