The Google Maps Android API v2 doesn't provide any functionality for navigation. It is in contradiction with Terms of Service of Maps APIs. Have a look at section 10.4 c (iii) of ToS:
No navigation. You will not use the Service or Content for or in connection with (a) real-time navigation or route guidance; or (b) automatic or autonomous vehicle control.
https://developers.google.com/maps/terms#section_10_4
If you need navigation you should create an intent that opens the Google Maps app in navigation mode. There is a Google Maps URLs that allows to construct a universal, cross-platform URL to launch Google Maps intents from your application. You can open navigation mode of native app following this documentation:
https://developers.google.com/maps/documentation/urls/guide#directions-action
Hope this helps!