Mark device as healthy if checkHealth function does not receive unhealthy event

[Zeel-Patel]

Solves: 1014 Currently, if device is marked as unhealthy, it's status remain unhealthy and kubelet does not show resource on node.

The ListAndWatch stream Receiver of kubelet device manager checks health of device and takes action to update node resources.

Making the change in checkHealth function to send device healthy signal (using healthy channel) to server ListAndWatch to update device health as healthy in case no event related to device unhealthy is received