Previously, the operator checked the ProxyGroup status fields for
information on how many of the proxies had successfully authed. Use
their state Secrets instead as a more reliable source of truth.
containerboot has written device_fqdn and device_ips keys to the
state Secret since inception, and pod_uid since 1.78.0, so there's
no need to use the API for that data. Read it from the state Secret
for consistency. However, to ensure we don't read data from a
previous run of containerboot, make sure we reset containerboot's
state keys on startup.
One other knock-on effect of that is ProxyGroups can briefly be
marked not Ready while a Pod is restarting. Introduce a new
ProxyGroupAvailable condition to more accurately reflect
when downstream controllers can implement flows that rely on a
ProxyGroup having at least 1 proxy Pod running.
Fixes#16327
Change-Id: I026c18e9d23e87109a471a87b8e4fb6271716a66
Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>