remove .gce_x86 suffix from ssh output files (post_install_cmd is not supported in jb-mr1 and before). Change-Id: I187386c699f22d80bac4c7f8c1e12ee5a590fb55 (cherry picked from commit 0c94e12da1d82c05a136cb5a0ed71dfe0f8a1b0c)