Defining Java Acceptance Test Stage

Moved Acceptance Test stage definition from Storage definition introduced in osdu/platform/system/storage!952 (merged)

Currently, only Storage service has acceptance tests defined. The stage will run only if the env variable ACCEPTANCE_TEST_DIR has been set, otherwise the stage will be skipped. This is a test pipeline run for Storage service when tests exist: https://community.opengroup.org/osdu/platform/system/storage/-/pipelines/291535. This is a test pipeline run for Partition when the tests do not exist: https://community.opengroup.org/osdu/platform/system/partition/-/pipelines/291536.