Add a check to make sure Google Play Services is available

MyTracks/project.properties

@@ -0,0 +1,16 @@
+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must be checked in Version Control Systems.
+#
+# To customize properties used by the Ant build system use,
+# "ant.properties", and override values to adapt the script to your
+# project structure.
+
+# Indicates whether an apk should be generated for each density.
+split.density=false
+proguard.config=proguard.cfg
+# Project target.
+target=Google Inc.:Google APIs:16
+android.library.reference.1=../MyTracksLib
+android.library.reference.2=../google_play_services_lib