Release leader election lease on shutdown

[joelanford]

In #1683, we fixed an issue related to flaky upgrade e2e tests that were a result of longer election times caused by #1663 (which was an intentional change to be tolerant to longer periods of apiserver downtime or heavy load)

As part of 1683, we bumped a test timeout to account for the new leader election settings.

My spidey sense always goes off when I see a timeout get bumped up in our tests. After some disucssion with other maintainers, I propose that we:

1. Revert the change to the upgrade e2e test (i.e. test/upgrade-e2e/post_upgrade_test.go) from 1683.
2. Set LeaderElectionReleaseOnCancel: true in our manager options for both catalogd and operator-controller.