Automatic merge from submit-queue (batch tested with PRs 50378, 51463, 50006, 51962, 51673). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>..
Add unit test case for Networkpolicy storage
**What this PR does / why we need it**:
add unit test for storage of resource Networkpolicy
Currently setting watch cache size for a given resource does not disable
the watch cache. This commit adds a new `default-watch-cache-size` flag
to map to the existing field, and refactors how watch cache sizes are
calculated to bring all of the code into one place. It also adds debug
logging to startup to allow us to verify watch cache enablement in
production.