Introduce two new flags to configure the ttl of an artifact and the max
no. of files to retain for an artifact. Modify the gc process to
consider the options and use timeouts to prevent the controller from
hanging.
This helps in situations when the SC has already garbage collected the
current artifact but the advertised artifact url is still the same,
which leads to the server returning a 404.
Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>
f8c27a85dd