custom_rules.xml

<?xml version="1.0" encoding="utf-8"?>
<project name="custom_rules" default="debug">
	<import file="custom_rules_multidex.xml" optional="true" />

	<fail
		message="sdk.dir is missing. Make sure to generate local.properties using 'android update project' or to inject it through the ANDROID_HOME environment variable."
		unless="sdk.dir"
	/>
    
	<path id="android.antlibs">
		<pathelement path="${sdk.dir}/tools/lib/ant-tasks.jar" />
	</path>
	
	<!-- Custom tasks -->
	<taskdef resource="anttasks.properties" classpathref="android.antlibs" />
	
	<condition property="exe" value=".exe" else=""><os family="windows" /></condition>
	<condition property="bat" value=".bat" else=""><os family="windows" /></condition>

	<getbuildtools name="android.build.tools.dir" verbose="${verbose}" />
	<property name="aapt" location="${android.build.tools.dir}/aapt${exe}" />
	<property name="aidl" location="${android.build.tools.dir}/aidl${exe}" />
	<property name="dx" location="${android.build.tools.dir}/dx${bat}" />
	<if>
        	<condition>
          		<resourceexists>
              			<file file="${android.build.tools.dir}/zipalign${exe}" />
			</resourceexists>
		</condition>
		<then>
			<property name="zipalign" location="${android.build.tools.dir}/zipalign${exe}" />
		</then>
		<else>
			<property name="android.tools.dir" location="${sdk.dir}/tools" />
			<property name="zipalign" location="${android.tools.dir}/zipalign${exe}" />
		</else>
	</if>

</project>