Add missing 96px icon for chrome://media-app.

It looks like like was missed in the conversion from mainifest.json
to web_app_info.

The IDR_MEDIA_APP_GALLERY_ICON_96_PNG is already plumbed through
chrome://media-app
https://source.chromium.org/search?q=IDR_MEDIA_APP_GALLERY_ICON_96_PNG
so I suspect this change just provides the 96px icon for web things
that use the manifest (e.g. pinning on the shelf).

Bug: b/161203411
Change-Id: I63d396434070938b6d462912336b9b3e9daf2d80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2497721Reviewed-by: Patti <patricialor@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: David Lei <dlei@google.com>
Cr-Commit-Position: refs/heads/master@{#820677}

chrome/browser/chromeos/web_applications/media_web_app_info.cc

@@ -64,6 +64,7 @@ std::unique_ptr<WebApplicationInfo> CreateWebAppInfoForMediaWebApp() {
           {"app_icon_32.png", 32, IDR_MEDIA_APP_GALLERY_ICON_32_PNG},
           {"app_icon_48.png", 48, IDR_MEDIA_APP_GALLERY_ICON_48_PNG},
           {"app_icon_64.png", 64, IDR_MEDIA_APP_GALLERY_ICON_64_PNG},
+          {"app_icon_96.png", 96, IDR_MEDIA_APP_GALLERY_ICON_96_PNG},
           {"app_icon_128.png", 128, IDR_MEDIA_APP_GALLERY_ICON_128_PNG},
           {"app_icon_192.png", 192, IDR_MEDIA_APP_GALLERY_ICON_192_PNG},
           {"app_icon_256.png", 256, IDR_MEDIA_APP_GALLERY_ICON_256_PNG},