Add REST test for:

* `.doc`
* `.docx`

The later fails with:

```
==> Test Info: seed=DB93397128B876D4; jvm=1; suite=1
Suite: org.elasticsearch.ingest.attachment.IngestAttachmentRestIT
  2> REPRODUCE WITH: gradle :plugins:ingest-attachment:integTest -Dtests.seed=DB93397128B876D4 -Dtests.class=org.elasticsearch.ingest.attachment.IngestAttachmentRestIT -Dtests.method="test {yaml=ingest_attachment/30_files_supported/Test ingest attachment processor with .docx file}" -Des.logger.level=WARN -Dtests.security.manager=true -Dtests.locale=bg -Dtests.timezone=Europe/Athens
FAILURE 4.53s | IngestAttachmentRestIT.test {yaml=ingest_attachment/30_files_supported/Test ingest attachment processor with .docx file} <<< FAILURES!
   > Throwable #1: java.lang.AssertionError: expected [2xx] status code but api [index] returned [400 Bad Request] [{"error":{"root_cause":[{"type":"parse_exception","reason":"Error parsing document in field [field1]"}],"type":"parse_exception","reason":"Error parsing document in field [field1]","caused_by":{"type":"tika_exception","reason":"Unexpected RuntimeException from org.apache.tika.parser.microsoft.ooxml.OOXMLParser@7f85baa5","caused_by":{"type":"illegal_state_exception","reason":"access denied (\"java.lang.RuntimePermission\" \"getClassLoader\")","caused_by":{"type":"access_control_exception","reason":"access denied (\"java.lang.RuntimePermission\" \"getClassLoader\")"}}}},"status":400}]
   >    at __randomizedtesting.SeedInfo.seed([DB93397128B876D4:53C706AB86441B2C]:0)
   >    at org.elasticsearch.test.rest.section.DoSection.execute(DoSection.java:107)
   >    at org.elasticsearch.test.rest.ESRestTestCase.test(ESRestTestCase.java:395)
   >    at java.lang.Thread.run(Thread.java:745)
```

Related to #16864