cmupdater: run abort in a non-uithread

onStartService runs in a UIThread, so we should run networking operations in a non-ui thread
to avoid NetworkOnMainThreadException errors.

Change-Id: I7eb087efdc2bb610bbc71ec581cc12ef477b77ef
JIRA: CYAN-4361
Issue: https://jira.cyanogenmod.org/browse/CYAN-4361
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>