amp-ima-video, how to send secure signals?

### Description

I'm not sure if this has been implemented already, but it seems that "secure signals" can now be sent to the ima sdk, has this been implemented in the amp-ima-video?

shows how secure signals can be sent, needsa confid for the networkid?
https://developers.google.com/interactive-media-ads/docs/sdks/html5/client-side/securesignals

### Alternatives Considered

not siure there is an alternative

### Additional Context

_No response_

Start with the amp-ima-video component and compare its current integration with the linked Google IMA secure-signals documentation. Determine whether secure signals are already supported and what network ID configuration the IMA SDK requires; done means the issue has a confirmed implementation status or a defined, tested integration path.

Written by the indexing model from the issue text.