This setting should've been set to False back ...

...with commit 9eb797b09916574c2a4e0f5f9ea61fe120879075

With this setting to True in the code, any tools anyone writes will
automatically start preallocating, which is almost always bad these days
with SSDs. So, if you write a tool that just scan dbs for stats, it'll
commit any pending info triggering preallocation and bam, your SSDs
start to fill up. :/

Anyway, back when I wrote 9eb797b09916574c2a4e0f5f9ea61fe120879075 it
was my intention to have this off by default, everywhere; I changed all
the settings points but I failed to change the dang constant itself.
This corrects that.

Change-Id: Iada0a3f1ecfabda4a96f574903d8e2eed1f69064
Merge "This setting should've been set to False back ..."