refactor: remove existing flutter android v1 embedding across plugins

[juliansteenbakker]

Description

Removes all reference to embedding v1.

Fix for #7157

Checklist

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Breaking Change

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[juliansteenbakker]

since firebase_admob is deprecated checks will fail because of it. (@russellwheatley)

[russellwheatley]

LGTM

[lesnitsky]

LGTM