gralloc: Use new ION API by default

This conditionally reverts commit b519bb243a1537f7420a2e81bbfa91d38d4ae8dc
and reverses the logic to use OLD_ION_API since NEW_ION_API
is the default.

Change-Id: I3708dff82207844302431296ccfc29421d104442
display-caf: remove -Werror flag for build