Embedded media example is throwing false negatives in Percy

**Describe the bug**

Our embedded media example uses external video and is very often failing in Percy due to some network or other issues causing false negatives on unrelated PRs.

We need to either change the example to make it work more consistent with Percy or find a way for Percy to ignore it.

Locate the embedded media example and reproduce its Percy failures, checking whether the external video is the source of the inconsistent snapshots. Done means the example produces reliable Percy results or is excluded from Percy coverage without causing unrelated pull requests to fail.

Written by the indexing model from the issue text.