ionic 3 and local storage (retain the local storage values even after deployment)

I am using ionic 3 to save user email id during login process using the following code.

localStorage.setItem('email_id', self.email);

Retrieve the same using

let shouldRemember = localStorage.getItem('shouldRemember');

Which works properly until i deploy a new version in App Store, the email ID value will get cleared, This problem occurs after new deployment to the app store.

How can i save the data so that even after the deployment i am able to get the value of the email ID.

from ionic 3 and local storage (retain the local storage values even after deployment)