Add suppress_type_name to stop warnings with ES7

When using elasticsearch 7 with fluentd, you seem to get a lot
of warnings in the docker logs output that look like:

    [types removal] Specifying types in bulk requests is deprecated.

The docs suggest adding suppress_type_name to stop these warnings,
and that seems to work without affecting any functionality.

Further info here:
https://github.com/uken/fluent-plugin-elasticsearch/issues/785

Closes-Bug: #1930856
Change-Id: I45be67df3717f78d78bcdc7df69600ab8681922f