Change ddmc run-test to make new objects instead of strings.

Before, the test was creating new strings until overflowing allocations,
which was half string objects and half character arrays. Now, it
allocates all strings with the character data, which is larger than
before, causing the test to run out of memory. Allocating only objects
prevents the test from running out of memory.

Change-Id: Icf3f0fd2ae847e76a9b8d5dfb762be92de16aaa3