[test] increase the waiting time in dbus tests (#563)
[test] increase the waiting time in dbus tests (#563)

We found failed cases where the Thread network has not been formed yet.
Increase the timeout to make it more stable.
jwhui/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,jwhui/borderrouter,openthread/ot-br-posix,openthread/borderrouter,bukepo/borderrouter,openthread/ot-br-posix,bukepo/borderrouter,bukepo/borderrouter,jwhui/borderrouter,bukepo/borderrouter,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,jwhui/borderrouter,jwhui/borderrouter,openthread/ot-br-posix,bukepo/borderrouter,openthread/borderrouter