etcd: Increase initial connection timeout to 15 minutes
etcd: Increase initial connection timeout to 15 minutes

Failing the agent can make it complicated to get everything up and running as
exponential backoff can cause cilium to not be running for a while which can
delay cilium-etcd from bootstrapping. This makes troubleshooting more
difficult.

Thus increase the timeout to 15 minutes to create a much larger overlap while
Cilium is up and running and etcd-operator can bring up a cluster in time.

Fixes: #6457

Signed-off-by: Thomas Graf <5f50a84c1fa3bcff146405017f36aec1a10a9e38@cilium.io>

cilium/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,cilium-team/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium-team/cilium,michi-covalent/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,cilium/cilium,cilium/cilium