Add backup/restore galera tests

Task: PROD-32647
Change-Id: I467ef1b899d15980eb62a1edaf13da75385e6836
diff --git a/src/com/mirantis/system_qa/SharedPipeline.groovy b/src/com/mirantis/system_qa/SharedPipeline.groovy
index bbf8415..0e0fdda 100644
--- a/src/com/mirantis/system_qa/SharedPipeline.groovy
+++ b/src/com/mirantis/system_qa/SharedPipeline.groovy
@@ -190,7 +190,7 @@
         run_cmd("""\
             if [ -n "$TCP_QA_REFS" ]; then
                 set -e
-                git fetch https://review.gerrithub.io/Mirantis/tcp-qa $TCP_QA_REFS && git checkout FETCH_HEAD || exit \$?
+                git reset --hard && git fetch https://review.gerrithub.io/Mirantis/tcp-qa $TCP_QA_REFS && git checkout FETCH_HEAD || exit \$?
             fi""")
         if (updateRequirements) {
             run_cmd("""\