init: Add the ability to start services with dynamic arguments.

    To add arguments dynamically to a service, start the service like so:

    setprop ctl.start service_to_run:arg1 arg2 arg3...

    To start a service with *no* dynamic arguments, start the service normally:

    setprop ctl.start service_to_run

    Dynamic arguments are only supported on 'oneshot' services

Signed-off-by: San Mehat <san@google.com>