Update ITs main (#2354)

Author: v1v

Jenkinsfile

@@ -13,7 +13,7 @@ pipeline {
     ELASTIC_DOCKER_SECRET = 'secret/apm-team/ci/docker-registry/prod'
     CODECOV_SECRET = 'secret/apm-team/ci/apm-agent-java-codecov'
     GITHUB_CHECK_ITS_NAME = 'Integration Tests'
-    ITS_PIPELINE = 'apm-integration-tests-selector-mbp/master'
+    ITS_PIPELINE = 'apm-integration-tests-selector-mbp/main'
     MAVEN_CONFIG = '-Dmaven.repo.local=.m2'
     OPBEANS_REPO = 'opbeans-java'
     JOB_GCS_BUCKET_STASH = 'apm-ci-temp'