LeakAwareDataBufferFactory#checkForLeaks automatically waits up to 5
sec for buffers to be released, which could be used as a way of
awaiting on some async logic to complete, and as long as buffers are
released, it shouldn't be long. However, the leak test in
LeakAwareDataBufferFactoryTests actually expects to find a leak, and
always ends up waiting the full 5 seconds.
This change, makes the wait configurable, with the no-arg method
using 0 (no waiting). AbstractLeakCheckingTests uses 1 second by
default since ResourceRegionEncoderTests did fail locally. If more
tests need this, we can adjust the settings.
3d89acf9ea