health metric: use instantaneous value

For health metric value update use the instantaneous value rather than
average value as initial average value calculation takes around 2 mins
because of window size requirement.

Change-Id: I5e53536b79374a75b1ddfa18ab7a6f782c5ae361
Signed-off-by: Jagpal Singh Gill <paligill@gmail.com>
1 file changed