Disable info messages by default for malloc debug.

Add a new option verbose for malloc debug that is not enabled by default.
This disables all of the info log messages. It turns out these log
messages can add a measurable amount of time and can change the boot up.

Bug: 129239269

Test: Adjusted unit tests pass.
Test: Verified no messages unless verbose option used.
Change-Id: I805cb7c8ecb44de88119574e59d784877cacc383