Simplify runChildProcess interface.
Simplify runChildProcess interface.

[#90093610]

cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux,shashidharatd/garden-linux,shashidharatd/garden-linux,cloudfoundry-incubator/garden-linux,cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux