change keep-running-on-failure flag default to true

## Background
- #4158 added support to not stop running on the first devloop if encountered any errors,
- This behavior is guarded by a flag keep-running-on-failure and it's default to false
- We would like to make the value to true when the feature is mature.
- The implementation current has some limitations
- It requires the user to press a key on his keyboard to restore the suspended dev session after he fixed errors he encountered during the first devloop
- We need to consider disable keep-running-on-failture feature for IDE integration, as it has some difficulties to send keyboard event to skaffold dev session, otherwise once dev session has been suspended, end user on IDE cannot restore the session. We can use ``user`` flag to implement this part of logic.
- We may also enable IDE user to restore dev session through API server in the future, but that is not in the scope of this issue.