[CI] Test user agent processor with non-ECS schema

[dnhatn]

Failed with unexpected warnings:

   java.lang.AssertionError: Failure at [ingest-useragent/20_useragent_processor:108]: got unexpected warning headers [
        299 Elasticsearch-7.7.0-SNAPSHOT-ca34817659734778d888c8f2d2a96a73dfac8e92 "the [os_major] property is deprecated for the user-agent processor"
        299 Elasticsearch-7.7.0-SNAPSHOT-ca34817659734778d888c8f2d2a96a73dfac8e92 "setting [ecs] to false for non-common schema format is deprecated and will be removed in 8.0, set to true or remove to use the non-deprecated format"
    ]

I can reproduce this locally one 7.x.

./gradlew ':modules:ingest-user-agent:integTestRunner' --tests "org.elasticsearch.ingest.useragent.IngestUserAgentClientYamlTestSuiteIT.test {yaml=ingest-useragent/20_useragent_processor/Test user agent processor with non-ECS schema}" -Dtests.seed=B21F63C099BA4F80 -Dtests.security.manager=true -Dtests.locale=en -Dtests.timezone=UCT -Dcompiler.java=13 -Dtests.fips.enabled=true

[elasticmachine]

Pinging @elastic/es-core-features (:Core/Features/Ingest)

[jkakavas]

This is a fips 140 related failure as it happens only in 7.x when running with tests.fips.enabled=true. 7.x matrix fips jobs are still flaky and I'm keeping track of all related issues. As such, I will close this for now and we can reopen if it persists once the fips job stabilizes