Because of recent changes to how coupons for the free tier are handled
(see commit 4c0817bcfb), we no longer want all these $10
non-expiring coupons. After coupons are applied during invoice
generation, if a customer does not have any valid (non expired, non
consumed) coupons, a new promotional coupon is applied.
We could just wait for users to consume all $10 of the non-expiring
coupons, and the new promotional coupon would be applied for the
following billing cycle, but this gets tricky, because if in the final
month, the user is billed for $1 of usage, but only $0.5 of the $10
non-expiring coupon is remaining, the user will be charged for the
remaining $0.5. With the new promotional coupon of $1.65, expiring every
month, this would not be an issue.
So long story short, this commit migrates all non-expiring coupons to
expire within 2 billing periods (all existing non-expiring coupons in
prod were created in early April or later). That way, there is still
enough value in the $10 coupon that we don't have to worry about
customers exceeding it, and the coupons will expire. Then we'll
immediately apply the $1.65 coupon for the next month! And then
hopefully this unfortunate situation will come to a pleasant end.
Change-Id: I8a593948d8876c41a71d886b9a95d4e2c802b4f3