comment out failing planning-result-test (#6400)
comment out failing planning-result-test (#6400)

temporarily address b/170869319

Closes #6400

COPYBARA_INTEGRATE_REVIEW=https://github.com/polymerlabs/arcs/pull/6400 from mmandlis:disable-test 6735950534bb4d96fcb7e4bb216e9f69b1f8226a
PiperOrigin-RevId: 337425362

PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs