getManifest(mPropertyBag) {
			if (!mPropertyBag.layer) {
				return Promise.reject("Layer must be provided");
			}
			if (!mPropertyBag.appVarUrl) {
				return Promise.reject("appVarUrl must be provided");
			}
			// Since this method is only called for Save As App Variant scenario on ABAP platform, the direct usage of write LrepConnector is triggered.
			return LrepConnector.appVariant.getManifest(mPropertyBag);
		}
Gets the manifest of an app(variant) from backend
@param {object} mPropertyBag - Object with parameters as properties
@param {sap.ui.fl.Layer} mPropertyBag.layer - Connectors are now determined based on the layer
@param {sap.ui.fl.Layer} mPropertyBag.appVarUrl - Contains full url of app variant manifest
@returns {Promise} Promise that resolves with the app(variant) manifest

@private
@ui5-restricted