Fixing Android builds with missing dependencies, making sure templates are up to date. Fixing include.xml as well for that

dependencies/extension-api/project.properties

@@ -0,0 +1,13 @@
+# 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,
+# "build.properties", and override values to adapt the script to your
+# project structure.
+
+android.library=true
+
+# Project target.
+target=android-::ANDROID_TARGET_SDK_VERSION::