healthcheck: update of healthcheck properties doesnt respawn healthcheck script

[Senthilnathan Murugappan]

Initially had delay, timeout and retries set to 5 secs and did a update of the same to 10s which though gets downloaded to the agent as is visible via http://10.84.7.42:8085/Snh_HealthCheckSandeshReq?uuid= but never respawns the healtcheck script with the correct args.

[Prabhjot Singh Sethi (prabhjot)]

script got restarted but agent didn't picked the updated params

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/16615
Submitter: Prabhjot Singh Sethi (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/16615
Committed: http://github.org/Juniper/contrail-controller/commit/d083d8760d3fc3dd0c282a738aa4dd5a3a505347
Submitter: Zuul
Branch: master

commit d083d8760d3fc3dd0c282a738aa4dd5a3a505347
Author: Prabhjot Singh Sethi <email address hidden>
Date: Thu Jan 28 21:42:58 2016 +0530

Fix Health Check script params update

Issue:
------
On receiving update on Health check params vrouter-agent
spawns script however it fails to update command params
for the same causing it to always run with older values
of IP, delay, timeout and other parameters

Fix:
----
Added method to update Instance task command parameter
when the script is stopped and started again it updates
command string before restarting the same

Closes-Bug: 1533832
Related-Bug: 1530539
Change-Id: Ifbd34a0760eb2fa2720dc8a4c71764b2a5dd342b