CCA: Add missing await when reviewing video

This await is missing in https://crrev.com/c/2237545.

Bug: b/166523553
Test: Launch CCA through Hangouts and video can be reviewed after
capturing

Change-Id: Idb9fe667bb887f42f094acfe88b9c45470967590
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2377019
Auto-Submit: Wei Lee <wtlee@chromium.org>
Reviewed-by: Inker Kuo <inker@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Commit-Queue: Inker Kuo <inker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802118}

chromeos/components/camera_app_ui/resources/src/js/views/camera/review_result.js

@@ -138,7 +138,7 @@ export class ReviewResult {
    *     with the video result.
    */
   async openVideo(fileEntry) {
-    this.reviewVideoResult_.src = pictureURL(fileEntry);
+    this.reviewVideoResult_.src = await pictureURL(fileEntry);
     state.set(state.State.REVIEW_VIDEO_RESULT, true);
     state.set(state.State.REVIEW_RESULT, true);
     this.confirmResultButton_.focus();