[7.x][ML] Alter ES integration test tasks (#1444)

Due to refactoring of the Elasticsearch build system we need
to use different task names when we run integration tests for
PRs.

Backport of #1442

Author: David Roberts

dev-tools/run_es_tests.sh

@@ -94,5 +94,5 @@ export GIT_COMMIT="$(git rev-parse HEAD)"
 export GIT_PREVIOUS_COMMIT="$GIT_COMMIT"
 
 IVY_REPO_URL="file://$2"
-./gradlew -Dbuild.ml_cpp.repo="$IVY_REPO_URL" :x-pack:plugin:ml:qa:native-multi-node-tests:integTestRunner
-./gradlew -Dbuild.ml_cpp.repo="$IVY_REPO_URL" :x-pack:plugin:integTestRunner --tests "org.elasticsearch.xpack.test.rest.XPackRestIT.test {p0=ml/*}"
+./gradlew -Dbuild.ml_cpp.repo="$IVY_REPO_URL" :x-pack:plugin:ml:qa:native-multi-node-tests:integTest
+./gradlew -Dbuild.ml_cpp.repo="$IVY_REPO_URL" :x-pack:plugin:integTest --tests "org.elasticsearch.xpack.test.rest.XPackRestIT.test {p0=ml/*}"