Fix migration issue with old filter queries

[stacey-gammon]

Summary

The code assumed that having a query property and not a meta property meant it was in a specific format (had a query_string property). This is not always the case.

fixes #41240

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

- [ ] This was checked for cross-browser compatibility, including a check against IE11
- [ ] Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
- [ ] Documentation was added for features that require explanation or tutorials

• Unit or functional tests were updated or added to match the most common scenarios
  - [ ] This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
  - [ ] This includes a feature addition or change that requires a release note and was labeled appropriately

[streamich]

Code LGTM.

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[bhavyarm]

This is not fixed on 7.3.0 snapshot from july 23rd. I get the same error. CC @marius-dr

[stacey-gammon]

Very interesting. https://github.com/elastic/kibana/pull/41269/files was merged into 7.3, and it actually changed the error message slightly...

   logger.warning(
      `Exception @ migrations730 while trying to migrate query filters!\nError:${e}\nSearchSource JSON:\n${doc.attributes.kibanaSavedObjectMeta.searchSourceJSON}`
    );

to give more information than the original error message:

 logger.warning(`Exception @ migrations730 while trying to migrate query filters! ${e}`);

I will checkout 7.3 branch and import the file to test.