[Elasticsearch][CCR] Change type nested to object

[constanca-m]

Summary

Currently there is a field of type nested in ccr metrics documents:

    - name: read_exceptions
      type: nested

However, the presence of this type blocks the migration to TSDB #5233:

cannot have nested fields when index is in [index.mode=time_series]

The read_exceptions property is used in this query and we should be able to change type nested into object without losing filtering capability.

AC

• read_exceptions is mapped as object
• ccr alert query filters both nested and object type of properties
• ccr alert query fires when expected with the new mapping type

[lalit-satapathy]

@martijnvg,

Can you comment on the above error from elasticsearch?