HDDS-11687. Robot warning: replace "is not" with "!=" (apache#7516)

Author: nandakumar131

hadoop-ozone/dist/src/main/smoketest/s3/bucketcreate.robot

@@ -46,9 +46,9 @@ Create new bucket and check no group ACL
     ${bucket} =         Create bucket
     ${acl} =            Execute     ozone sh bucket getacl s3v/${bucket}
     ${group} =          Get Regexp Matches   ${acl}     "GROUP"
-    IF      '${group}' is not '[]'
+    IF      '${group}' != '[]'
         ${json} =           Evaluate    json.loads('''${acl}''')    json
         # make sure this check is for group acl
         Should contain      ${json}[1][type]       GROUP
         Should contain      ${json}[1][aclList]    NONE
-    END
+    END