defconfigs: zram updates and regenerate

Change-Id: I69ee693a102247162e4695b806641b7552fa1d8b
(cherry picked from commit b5ad583ab5ae7142ce9b2d07af45055089cec557)
defconfigs: Disable cleancache

Change-Id: Ice9dd3f0b48f973c7e1a032bc25155aaa8298973
(cherry picked from commit 845be7a8b5234fe7839fe5c6e4fd3e374c1ec140)
add extra free kbytes tunable

Add a userspace visible knob to tell the VM to keep an extra amount
of memory free, by increasing the gap between each zone's min and
low watermarks.

This is useful for realtime applications that call system
calls and have a bound on the number of allocations that happen
in any short time period.  In this application, extra_free_kbytes
would be left at an amount equal to or larger than than the
maximum number of allocations that happen in any burst.

It may also be useful to reduce the memory use of virtual
machines (temporarily?), in a way that does not cause memory
fragmentation like ballooning does.

[ccross]
Revived for use on old kernels where no other solution exists.
The tunable will be removed on kernels that do better at avoiding
direct reclaim.

Change-Id: I765a42be8e964bfd3e2886d1ca85a29d60c3bb3e
Signed-off-by: Rik van Riel<riel@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>