Fix startup mount error on Parallels 14 guest tools

[max-arnold]

Description

This is a workaround for the following error (happens on first startup with the latest Parallels Tools):

Failed to mount folders in Linux guest. This is usually because
the "prl_fs" file system is not available. Please verify that
Parallels Tools are properly installed in the guest and
can work properly. If so, the VM reboot can solve a problem.
The command attempted was:

mount -t prl_fs -o uid=`id -u vagrant`,gid=`getent group vagrant | cut -d: -f3` media_DockerData /media/DockerData
mount -t prl_fs -o uid=`id -u vagrant`,gid=`id -g vagrant` media_DockerData /media/DockerData

Issues Resolved

#1115

[sttts]

/lgtm

[legal90]

👍 LGTM.
It's the same what we have in vagrant-parallels: https://github.com/Parallels/vagrant-parallels/blob/master/lib/vagrant-parallels/guest_cap/linux/mount_parallels_shared_folder.rb#L98-L109

But due to the Parallels/vagrant-parallels#325 we need to have it applied on the box build time.

[cheeseplus]

Thanks a bunch, will pass this through the builders and see how it fares!