Depend on nvidia-container-toolkit package instead of nvidia-container-runtime

This change ensures that nvidia-docker2 depends on nvidia-container-toolkit instead of the nvidia-container-runtime package.

root@85b501a39a28:/local-repository# apt-get install --no-install-recommends nvidia-docker2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libcap2 libnvidia-container-tools libnvidia-container1 nvidia-container-toolkit
The following NEW packages will be installed:
  libcap2 libnvidia-container-tools libnvidia-container1 nvidia-container-toolkit nvidia-docker2
0 upgraded, 5 newly installed, 0 to remove and 5 not upgraded.
Need to get 13.0 kB/1082 kB of archives.
After this operation, 4778 kB of additional disk space will be used.
Do you want to continue? [Y/n]

Unpacking nvidia-docker2 (2.6.1~rc.1-1) ...
Setting up libcap2:amd64 (1:2.25-1.2) ...
Setting up libnvidia-container1:amd64 (1.5.0-1) ...
Setting up libnvidia-container-tools (1.5.0-1) ...
Setting up nvidia-container-toolkit (1.5.2~rc.1-1) ...
Setting up nvidia-docker2 (2.6.1~rc.1-1) ...
Processing triggers for libc-bin (2.27-3ubuntu1.4) ...

container-toolkit!45 (merged)

Signed-off-by: Evan Lezar elezar@nvidia.com