retryBlockImageCountCheck aborted the whole wait on the first rbd ls
failure. The listing runs through the toolbox under a timeout and can
fail transiently right after the pool is created (observed as exit
status 124 while the pool PGs were still being created), turning a
recoverable delay into an immediate test failure.
Keep retrying on listing errors and double the retry budget: when the
first provisioning attempt fails, the external-provisioner sidecar
backs off exponentially and its next attempt can be several minutes
out, which the previous 275s budget could not ride out.
This commit also bumps the snapshot controller wait in the block test
from 75s to 450s; the snapshot-controller image pull can take longer
than 75s in CI.
Signed-off-by: Joshua Hoblitt <josh@hoblitt.com>