chore: depend on mojo audio and video in BUILD.gn

[codebytere]

Description of Change

Follow up for #16763.

We need to depend on
"//services/video_capture/public/mojom:constants"
"//services/audio/public/mojom:constants"
for Electron to build.

cc @brenca

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: none

[release-clerk]

No Release Notes

[trop]

I have automatically backported this PR to "5-0-x", please check out #16789

[deepak1556]

@codebytere how did the original PR pass the builds when this was needed ?

[codebytere]

@deepak1556 idk but that concerns me: i checked and they did

[deepak1556]

They are private deps and the required headers are generated ones, thats why I didn't worry about adding them explicitly. Nevertheless, its good to have them explicitly specified.

//electron:electron_lib --[private]-->
//content/public/app:both --[private]-->
//content/public/utility:utility_sources --[private]-->
//content/utility:utility --[private]-->
//services/video_capture/public/mojom:constants