atrace: enable running on user builds

This change allows atrace to be run on a user build, where it is not run as
root.  Some command line options still require root, and atrace will refuse to
run if those options are specified when run as non-root.

Bug: 6513400
Change-Id: I29984cb8a7c3ad80ba5fa6b031ed8ff81acabacf
diff --git a/cmds/atrace/Android.mk b/cmds/atrace/Android.mk
index 1de8e95..12526d0 100644
--- a/cmds/atrace/Android.mk
+++ b/cmds/atrace/Android.mk
@@ -10,8 +10,8 @@
 
 LOCAL_MODULE:= atrace
 
-LOCAL_MODULE_TAGS:= debug
+LOCAL_MODULE_TAGS:= optional
 
-LOCAL_STATIC_LIBRARIES := libz
+LOCAL_SHARED_LIBRARIES := libz
 
 include $(BUILD_EXECUTABLE)