Vary decoder buffer size in property tests.
Vary decoder buffer size in property tests.

This should stress the suspending/resuming as buffers fill more often.

jordandcarter/heatshrink,senyor/heatshrink,senyor/heatshrink,atomicobject/heatshrink,jordandcarter/heatshrink,atomicobject/heatshrink,silentbicycle/heatshrink,silentbicycle/heatshrink