Replacement takes effect when the old plan expires, and the new price will be charged at the same time.
Replacement takes effect immediately, and the user is charged full price of new plan and is given a full billing cycle of subscription, plus remaining prorated time from the old plan.
Replacement takes effect immediately, and the billing cycle remains the same. The price for the remaining period will be charged. This option is only available for subscription upgrade.
Replacement takes effect immediately, and the new price will be charged on next recurrence time. The billing cycle stays the same.
Replacement takes effect immediately, and the remaining time will be prorated and credited to the user. This is the current default behavior.
Enum with possible proration modes in a subscription upgrade or downgrade in the Play Store. Used only for Google.