Checkpoint restore via CreateContainer was intended to be experimental,
but was enabled by default. While the enable_criu knob can disable CRIU
entirely, explicit forensic checkpoints still benefit from CRIU while
restore via CreateContainer should be disabled by default.
Add the enable_experimental_restore_via_create configuration knob to
control restore via CreateContainer independently from enable_criu,
defaulting to disabled.
Assisted-by: Antigravity
Signed-off-by: Samuel Karp <samuelkarp@google.com>