Check for IControllOffload.getServer() returning null

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
Bug: 29337859
Bug: 65529504

Merged-In: I5a57a9fd14dc53eaf1722fbc9a972f4f73280497
Merged-In: Ib2d1862367145260ac83f14d181646eb827538f8
Change-Id: I671487344000f1f2db92b8e4a693c096b680830c
(cherry picked from commit 87b3bfd5)