UDID.randomUUID collision in Android

I understand that UDID.randomUUID is mostly good: how good is java's UUID.randomUUID?

Has anyone experienced a problem on Android with UDID.randomUUID. Since Android uses Dalvik VM.

I am not able to reproduce a collision. However, the following code is suspicious (based on reports from my Production) and may result into a collision while running on two different processes (Two apps with the same code and different packages, for example free app vs pro app)?

private static final String PREFIX = Long.toString(UUID.randomUUID().getLeastSignificantBits());

Any thoughts/experience would be helpful!