Making //test/integration:hds_integration_test test faster and more r…

…obust (#4164)

Follow up on #4149.

I increased any unused timers to 100 seconds. Additionally, instead of waiting on a timer to go off, all but one tests wait on cluster stats to change.
I decreased the timer wait times, reducing the test runtime from 25 seconds to 5.

Exceptions:

While TCP health checking, if an endpoint responds with a wrong phrase, the cluster failure stats do not change. So, the one test that examines this case still depends on timers.
There are 2 tests that test hosts timing out. I set those timeouts to 0.1 seconds (vs 100). However, both tests still wait on the cluster stats to change.
Risk Level:
Low

Testing:
I run the test locally, and it passed 3000/3000 times.

This work is for #1310.

Signed-off-by: markatou <[email protected]>