contint: Graphviz on Jenkins slaves

We are going to generate documentation using Doxygen which can generate
graphs using 'dot' provided by the graphviz package.

graphviz is a pre-existing dependency for the Jenkins master gallium
which is also a slave. To avoid duplicate definition, make use of
the new require_package().

Bug: 72454
Change-Id: Iab7b1288478f1534fd3e34f7e486656d88129ec1
Merge "contint: Graphviz on Jenkins slaves" into production