submodule: bump third_party/openthread/repo from `9fcdbed` to `a201e9d` (#1247)
submodule: bump third_party/openthread/repo from `9fcdbed` to `a201e9d` (#1247)

openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter