Add proper xml header to xml files

Change-Id: I06b5fb3799bc4be09f6ec9ea34acbdc5ee6593de
Stop feeding the Oozie's site libpath twice into Oozie

Oozies site libpath [1] already points to
/user/oozie/share/lib. Hence, there is not need to pass it once again
as custom per-job libpath.

[1] See property oozie.service.WorkflowAppService.system.libpath

Change-Id: I725965aeb3c860d6416ff5adb1b3fade4f021ced