Changed ping-time metric short name to Ping Time
Changed ping-time metric short name to Ping Time

Signed-off-by: GabrielNicolasAvellaneda <83a8591a9a34d9745961eaad83d1d871cc3e5445@gmail.com>

jdgwartney/boundary-plugin-ping-check,boundary/boundary-plugin-ping-check,GabrielNicolasAvellaneda/boundary-plugin-ping-check