Make run_on_app_dump.py run with python3

Change-Id: I054acf4f25658c66ad4156217009fc48c678374e
diff --git a/tools/gradle.py b/tools/gradle.py
index a52e3f3..b6f5187 100755
--- a/tools/gradle.py
+++ b/tools/gradle.py
@@ -47,7 +47,7 @@
 def PrintCmd(s):
   if type(s) is list:
     s = ' '.join(s)
-  print 'Running: %s' % s
+  print('Running: %s' % s)
   # I know this will hit os on windows eventually if we don't do this.
   sys.stdout.flush()