Maybe fix issue #17449495: Nakasi is pretty laggy/slow to do anything

Tweak the oom tuning to raise everything by 50%.  This is the same
increase we did for Volantis; I am thinking that most of the issue
there was not it being 64 bit, but it being tighter on RAM.  From
my testing, it looks like in user switching there was some paging
going on with Nakasi, and with this change things seem to be better.

We should probably revisit this for future work on RAM.  It seems
likely that a 64 bit device will need more RAM, so probably the value
I am picking here is larger than we actually need for other devices.
I think this is the safest change at this point though -- it leaves
Volantis the same, where we already had tweaked it to address paging
issues, raises it on Nakasi (to the same value as Volantis) where we
seem to have paging issues, and on our other devices also raises it
but those are generally not under memory pressure so this shouldn't
really make a difference.

Change-Id: Ib19394068734d322a015ed07370d9d4961877e4b