rootdir: init.rc: write default oom_adj before starting ueventd

Otherwise, ueventd's oom_adj value would have been 0 and it could
easily get killed early during low memory events

Change-Id: I1adbd18c37215b26ae77e70f7b8dbd1e143fc2d4
Signed-off-by: Dima Zavin <dima@android.com>