Fix buildbot failure for 098-ddmc test

Fix buildbot failure for 098-ddmc test

The test only failed on buildbot but not on my local machine. It is
possibly caused by GC reclaiming dead objects and associated allocation
records.

More importantly, the CL 153435 changes the behavior of recent allocation
tracking for DDMS, so that it now reports allocation records of not-yet-
garbaged-collected objects. They are a superset of live objects, but not
a precise set of the most recent allocations.

Bug: 20037135
Change-Id: I200a6c8baaeb98207845049902d59efa2f4ea11e