pick up a random port for metrics when MountPod using hostNetwork

[fungaren]

As the MountPod can inherit some attributes from juicefs-csi-node daemonset:

	// inherit attr from csi
	jfsSetting.Attr = PodAttr{
		Namespace:            Namespace,
		MountPointPath:       MountPointPath,
		JFSConfigPath:        JFSConfigPath,
		JFSMountPriorityName: JFSMountPriorityName,
		Image:                MountImage,
		HostNetwork:          CSIPod.Spec.HostNetwork,
		HostAliases:          CSIPod.Spec.HostAliases,
		HostPID:              CSIPod.Spec.HostPID,
		HostIPC:              CSIPod.Spec.HostIPC,
		DNSConfig:            CSIPod.Spec.DNSConfig,
		DNSPolicy:            CSIPod.Spec.DNSPolicy,
		ImagePullSecrets:     CSIPod.Spec.ImagePullSecrets,
		PreemptionPolicy:     CSIPod.Spec.PreemptionPolicy,
		Tolerations:          CSIPod.Spec.Tolerations,
	}

So if we make juicefs-csi-node to be hostNetwork: true, those MountPods will also be hostNetwork: true. What makes the problem is those metrics exported by juicefs mount if these MountPods listen at the same port.

kube-system   juicefs-e-node-s19inspur-36c7-pvc-36e2d025-c704-45e1-8784-43b63daa9092-sugiun   1/1     Running             0          9m13s   x.x.x.x   e-node-s19inspur-36c7    <none>           <none>
kube-system   juicefs-e-node-s19inspur-36c7-pvc-e2ee0faf-6642-4128-9917-f656b4d9aec1-tccate   0/1     NodePorts           0          12s     <none>           e-node-s19inspur-36c7    <none>           <none>

Status:               Failed
Reason:               NodePorts
Message:              Pod Predicate NodePorts failed

This PR makes these MountPods listen at a random port when they are in hostNetwork mode, and we also do not proclaim any container port.

[codecov-commenter]

Codecov Report

Base: 41.52% // Head: 41.44% // Decreases project coverage by -0.08% ⚠️

Coverage data is based on head (2cc6adb) compared to base (173a77d).
Patch coverage: 33.33% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #586      +/-   ##
==========================================
- Coverage   41.52%   41.44%   -0.08%     
==========================================
  Files          32       32              
  Lines        3374     3380       +6     
==========================================
  Hits         1401     1401              
- Misses       1851     1853       +2     
- Partials      122      126       +4     

Impacted Files	Coverage Δ
pkg/juicefs/mount/builder/pod.go	55.88% <33.33%> (-2.58%)	⬇️

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[Hexilee]

LGTM