[amp-next-page] Request replaceHistory failed console error on viewer

## What's the issue?

When viewing a page on AMP viewer that loads next pages via the amp-next-page, there are the following console errors:
```
//history-impl.js:289
Uncaught (in promise) History: failed to execute a task:: Request replaceHistory failed: sb
at wb.push.f.m.Ga (https://cdn.ampproject.org/rtv/012012301722001/v0/amp-viewer-integration-0.1.js:56:367)
at https://cdn.ampproject.org/rtv/012012301722001/v0/amp-viewer-integration-0.1.js:54:686
```

## How do we reproduce the issue?

Please provide a public URL and ideally a reduced test case (e.g. on jsbin.com) that exhibits only your issue and nothing else. Provide step-by-step instructions for reproducing the issue:

1. Open google.com in mobile view. Search for "cnet electric eels"
2. Click on the first result on SERP
3. Scroll down to let the next page load. View the console in CDT.

## What browsers are affected?

All

## Which AMP version is affected?

Version 2101230412003

Start by reproducing the console error with amp-next-page in the AMP viewer using the listed Google mobile-search steps, and inspect the reported history-impl.js and amp-viewer-integration-0.1.js locations. Done means the next-page flow no longer logs the failed replaceHistory error in affected browsers.

Written by the indexing model from the issue text.