title: Account manager and signing key update through Google App Sign
body: <p>My goal is to share user credentials between my apps using AccountManager. To do this I need to ensure that signatures of both apps is the same. The problem is that these 2 applications have different signing keys, fortunately Google allows us to generate a common key for both applications and upload it to Google App Sign for both apps. But documentation says:</p>
  <p><em>If you publish your app to Google Play, you can upgrade the signing key for your published app through the Play Console—your new key is used to sign new installs and app updates, while your older app signing key is used to sign updates for users who installed your app before the key upgrade.</em></p>
  <p>Does it mean that for users who installed app before the key update they will not be able to share account through AccountManager because of difference of signing keys?</p>