Added a test vector that exercises lpf deltas

Added a test vector that exercises lpf deltas

From frame 2, the lpf deltas are all cleared for for even frames, and
a set of values are set and used for odd frames. The intention is to
exercise decoding code around lpf delta/update decoding.

Change-Id: Ic9ff1bc2c2a023f4805852f8573398f2ec2249d7