Add log group to rild to improve log collection on modem issue

Add log group to ril-daemon service. rild is the best place to
know the issue on the modem in many time. It would be helpful
if rild alone can capture the snapshot of logcat buffers at
the moment of problem.

Change-Id: Ie0dcda126fb748a00e650427de35541672359287
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 7b151f2..5102565 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -397,7 +397,7 @@
     socket rild stream 660 root radio
     socket rild-debug stream 660 radio system
     user root
-    group radio cache inet misc audio sdcard_rw
+    group radio cache inet misc audio sdcard_rw log
 
 service surfaceflinger /system/bin/surfaceflinger
     class main