Posts/Pages cache are not cleared on update with AMP plugin

[jeawhanlee]

Describe the bug
Related cache of pages/posts are not cleared on update with AMP Plugin activated.

To Reproduce
Steps to reproduce the behavior:

1. Install AMP plugin & activate
2. Remove trailing slash from permalink settings
3. Visit some pages with amp query. e.g example.org/hello-world?amp
4. See that page is cached
5. Edit page
6. Cache of edited page is not cleared

Expected behavior
Related cache should be cleared when page/post is updated

Screenshots
N/A

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
issue first discovered here: #7526 (comment)