Fix possibility of double-encoded local_storage value in cookie storage
Fix possibility of double-encoded local_storage value in cookie storage

Due to the inconsistent migration, some users do have
double-encoded campaigns in their cookie. The value is
in the format used only for local storage.

This change fixes the issue and stores the updated
object to the cookie correctly.

remp2020/remp,remp2020/remp,remp2020/remp,remp2020/remp,remp2020/remp