[ContentBundle] Fix for static content not saving (issue 2129)

| Q             | A
| ------------- | ---
| Bug fix?      | [yes]
| New feature?  | [no]
| BC breaks?    | [no]
| Deprecations? | [no]
| Tests pass?   | [yes]
| Fixed tickets | #2129 
| License       | 
| Doc PR        |