Remove GCE client secret file from pipeline integration tests terraform configs.
Remove GCE client secret file from pipeline integration tests terraform configs.

[#90668534]

Signed-off-by: David Wadden <ff4ebafbe4a7d77cde45f9afefafd7a5dfa94f36@pivotal.io>

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