Pinging @elastic/es-storage-engine (Team:StorageEngine)

This is meant as a fix for #134969 ... but to be honest I'm not confident that this is the correct way to handle this issue. It's also possible that I messed something up during the rename.

I think we will also need to guard the YAML test.

REPRODUCE WITH: ./gradlew ":x-pack:plugin:logsdb:yamlRestTest" --tests "org.elasticsearch.xpack.logsdb.LogsdbTestSuiteIT.test {yaml=patterntext/30_template_id/Sort by template_id ascending from request}" -Dtests.seed=4861448B902F5F9A -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false" -Dlicense.key=x-pack/license-tools/src/test/resources/public.key -Dtests.locale=lu-Latn-CD -Dtests.timezone=Asia/Omsk -Druntime.java=24

Last time I had yaml tests that depended on a snapshot-only feature flag, the delivery team advised I do something like: df518aa. We'll probably need to do something similar here.

I see that LogsdbTestSuiteIT already sets up the test cluster with pattern text feature flag. This should be sufficient to avoid these test failures.

As part of the the rename from patterned_text to pattern_text, the FeatureFlag.PATTERN_TEXT name wasn't updated. Pushed a fix for this.