Heartbeat check.response.code multiple values

Elastic Stack Beats
2

@Jugsofbeer I agree this could be improved, or at the very least better documented. The conditions there use the standard beats condition processors, which includes a logical or! So, for your use case:

- or:
  - equals:  
      http.response.code: 200
  - equals:
      http.response.code: 502
  - equals:
      http.response.code: 503

should do the trick.

Perhaps we could still improve the experience by having a new type of equality check other than equals. Something like equals_any: {of: [200, 502, 503], in: 'http.response.code' which would be more terse.

Thoughts? CC @ruflin