Unlike odp that has anim:iterate (IterateContainer) node,
both parallel time container and interate container appear
as p:par in ooxml so that we have to alter the node type
in the end. We also have to set the target of the iterate
container to make animation work.

Change-Id: Ic50b5f1d85716a67712ed1e812bcb0e7f25fb5a8
Reviewed-on: https://gerrit.libreoffice.org/58576
Tested-by: Jenkins
Reviewed-by: Mark Hung <marklh9@gmail.com>