Update OOM adj levels.

This introduces some new buckets that will be used by the activity
manager, and adjusts the default levels to match what we had been
setting for Droid.

It turns out Passion has been using the old levels, which makes no
sense for how much memory it has.  Also it is a problem with these
definitions spreading to other projects for different devices, so
I am going to update the defaults to be appropriate for our newer
devices, and put here a file to tune them down for something like
the sapphire.

Change-Id: Ia4f33c4c3b94aeb3656f60b9222072a1d11e9e68