Fix CommandPool reallocation bugs

Fix CommandPool reallocation bugs

When fixedCapacity is > 0 and data.size() == fixedCapacity,
There was some logical bugs when data.size() == offset + count.

We can hold 'data.size()'`s data, and after Allocate(count),
we will hold 'offset + count'`s data.
So we should reallocate only data.size() < offset + count.

+

Furthermore, We just set default Command Pool Increment as 32kb exactly.
Previous code increase 32 * sizeof(Command) kb = 2MB for each command pool.

Change-Id: I5e845839057bc75c40c275e884b7677fe2c4d812
Signed-off-by: Eunki, Hong <eunkiki.hong@samsung.com>