Change Fuchsia in-tree Xi location to //third_party
Change Fuchsia in-tree Xi location to //third_party

modelorganism/xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,modelorganism/xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,fuchsia-mirror/third_party-xi-editor,modelorganism/xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,google/xi-editor