Some eventing e2e test helpers before and including release-0.22 use SubscriptionV1 when they mean to use SubscriptionV1Beta1 in ChannelChainTestHelper, and vice-versa. This is fixed in eventing HEAD. After https://github.com/google/knative-gcp/pull/2199, and the deprecation of SubscriptionV1Beta1, we should go back to using SubscriptionV1 in the e2e tests.
Some eventing e2e test helpers before and including release-0.22 use SubscriptionV1 when they mean to use SubscriptionV1Beta1 in ChannelChainTestHelper, and vice-versa. This is fixed in eventing HEAD. After https://github.com/google/knative-gcp/pull/2199, and the deprecation of SubscriptionV1Beta1, we should go back to using SubscriptionV1 in the e2e tests.