roomservice: support new manifest formats.

.repo/manifest.xml is no longer a symlink becuase apparently windows
developers need to use repo and windows needs admin for symlinks.

https: //gerrit.googlesource.com/git-repo/+/a269b1cb9dc21dfd598bfea3766206b606ad4589
Change-Id: I88ea0295133959136d7214f13a76b66d89dc88d4