Update Ubuntu base image for google terraform.
Update Ubuntu base image for google terraform.

Signed-off-by: Kristie-Lynne Koss <b6ebd6e8bc77ed89e2b529234243864da8b54e7b@pivotal.io>

svrc-pivotal/lattice,felipeg48/lattice,davidwadden/lattice,datachand/lattice,davidwadden/lattice-release,Klaudit/lattice,cloudfoundry-incubator/ltc,SrinivasChilveri/lattice,datachand/lattice,davidwadden/lattice,datachand/lattice,svrc-pivotal/lattice,Klaudit/lattice,svrc-pivotal/lattice,SrinivasChilveri/lattice,datachand/lattice,cloudfoundry-incubator/ltc,svrc-pivotal/lattice,davidwadden/lattice-release,Klaudit/lattice,SrinivasChilveri/lattice,felipeg48/lattice,Klaudit/lattice,SrinivasChilveri/lattice