Allow templating of updateStrategy for worker DaemonSet

[jon-rei]

What would you like to be added:

Currently, the default updateStrategy for the DaemonSet is used, which is the following by default

    updateStrategy:
      rollingUpdate:
        maxSurge: 0
        maxUnavailable: 1

The whole updateStrategy should be templatable with Helm to adjust the maxUnavailable setting or even other settings.

Why is this needed:

In our environment, we have hundreds of nodes, so a rollout takes a long time. Also, if a node is unhealthy, the rollout will stop. To overcome this, we always set maxUnavailable to 10% to speed up the rollout.

I could do a PR myself if this is useful.