fix(messaging, types): isSupported signature should be Promise<boolean> not boolean (#8798)

Author: MichaelVerdon

packages/messaging/lib/modular/index.d.ts

@@ -310,7 +310,7 @@ export function isDeliveryMetricsExportToBigQueryEnabled(messaging: Messaging):
  * @param messaging - Messaging instance.
  * @returns A boolean indicating if the APIs are supported.
  */
-export function isSupported(messaging: Messaging): boolean;
+export function isSupported(messaging: Messaging): Promise<boolean>;
 
 /**
  * Sets whether message delivery metrics are exported to BigQuery is enabled or disabled.

packages/messaging/lib/modular/index.js

@@ -344,7 +344,7 @@ export function setNotificationDelegationEnabled(messaging, enabled) {
 /**
  * Checks if all required APIs exist in the browser.
  * @param {Messaging} messaging - Messaging instance.
- * @returns {boolean}
+ * @returns {Promise<boolean>}
  */
 export function isSupported(messaging) {
   return messaging.isSupported.call(messaging, MODULAR_DEPRECATION_ARG);