systrace: rename the tags property

Change-Id: Ie326b4bd8647cda55501a9635f50bc2b2c69147a
diff --git a/systrace.py b/systrace.py
index 7adb1af..dd53a61 100755
--- a/systrace.py
+++ b/systrace.py
@@ -59,7 +59,7 @@
       except KeyError:
         parser.error('unrecognized tag: %s\nknown tags are: %s' %
                      (tag, ', '.join(trace_tag_bits.iterkeys())))
-    atrace_args = ['adb', 'shell', 'setprop', 'atrace.tags.enableflags', hex(flags)]
+    atrace_args = ['adb', 'shell', 'setprop', 'debug.atrace.tags.enableflags', hex(flags)]
     try:
       subprocess.check_call(atrace_args)
     except subprocess.CalledProcessError, e: