Include sysstat package on xtrabackup nodes by default

Related: PROD-28135
Fixes: PROD-29932

Change-Id: I18e93846806670f30664e27dda3efbf78b720325
(cherry picked from commit 986c658cd97f2e790dcf7a03588c921765c79f6b)
diff --git a/xtrabackup/server/single.yml b/xtrabackup/server/single.yml
index 92d9fc3..ef5209a 100644
--- a/xtrabackup/server/single.yml
+++ b/xtrabackup/server/single.yml
@@ -13,3 +13,6 @@
         user:
           xtrabackup:
             enabled: true
+      package:
+        sysstat:
+          version: latest
\ No newline at end of file