logd: Use Minijail for privilege dropping.

Makes code smaller, removes duplication. Using Minijail also allows
adding further sandboxing down the road.

Bug: 30156807
Change-Id: I8fa242fba545049ee82f6655fe6ecc14c53fcab7
diff --git a/logd/Android.mk b/logd/Android.mk
index 84ea7a2..3348890 100644
--- a/logd/Android.mk
+++ b/logd/Android.mk
@@ -28,7 +28,8 @@
     liblog \
     libcutils \
     libbase \
-    libpackagelistparser
+    libpackagelistparser \
+    libminijail
 
 # This is what we want to do:
 #  event_logtags = $(shell \