This allows runsc flags to be set per sandbox instance. For
example, K8s pod annotations can be used to enable
--debug for a single pod, making troubleshoot much easier.
Similarly, features like --vfs2 can be enabled for
experimentation without affecting other pods in the node.
Closes#3494
PiperOrigin-RevId: 329542815
Use reflection and tags to provide automatic conversion from
Config to flags. This makes adding new flags less error-prone,
skips flags using default values (easier to read), and makes
tests correctly use default flag values for test Configs.
Updates #3494
PiperOrigin-RevId: 328662070
Fabricio Voznika