googleads-mobile-flutter: Strict Secure Cookie policy error in Admob after updating to Android 11

Bug report

Native ad cause crash app on simulator Android, API 30

Describe the bug https://stackoverflow.com/questions/64605612/strict-secure-cookie-policy-error-in-admob-after-updating-to-android-11

Steps to reproduce

Steps to reproduce the behavior:

1. Config native ad as codelab https://codelabs.developers.google.com/codelabs/admob-inline-ads-in-flutter#7
2. Run app on Android simular with API 30

Expected behavior

Firstly app run success but after 3s it was crash and throw the error:

Strict Secure Cookie policy does not allow setting a secure cookie for
http://googleads.g.doubleclick.net/ for apps targeting >= R. Please either use the 'https:' scheme for 
this URL or omit the 'Secure' directive in the cookie value.