test(app): spyToBeCalledOnceAsync should delegate to general Times

this removes duplicate code in the utility function

Author: mikehardy

tests/globals.js

@@ -117,22 +117,7 @@ global.Utils = {
     return result;
   },
   spyToBeCalledOnceAsync(spy, timeout = 5000) {
-    let interval;
-    const { resolve, reject, promise } = Promise.defer();
-    const timer = setTimeout(() => {
-      clearInterval(interval);
-      reject(new Error('Spy was not called within timeout period.'));
-    }, timeout);
-
-    interval = setInterval(() => {
-      if (spy.callCount > 0) {
-        clearTimeout(timer);
-        clearInterval(interval);
-        resolve();
-      }
-    }, 25);
-
-    return promise;
+    return this.spyToBeCalledTimesAsync(spy, 1, timeout);
   },
   spyToBeCalledTimesAsync(spy, times = 2, timeout = 5000) {
     let interval;