RootCanal: Reject random addresses that are empty

This case is not described in the command description
but the definition of random addresses does say that
address bits must not be all 0.

Bug: 245578454
Test: m root-canal
Ignore-AOSP-First: Cherry-picked from AOSP
Merged-In: I2ba51f6333723beb790759fdf683ebc79585d998
Change-Id: I2ba51f6333723beb790759fdf683ebc79585d998