custom_rules.xml

<project xmlns='antlib:org.apache.tools.ant'>


    <target name="-pre-build">
        <exec executable="ndk-build" failonerror="true"/>
     </target> 

    <target name="clean" depends="android_rules.clean">
        <exec executable="$(ndk-dir)/ndk-build" failonerror="true">
                <arg value="clean"/>
        </exec>
    </target>

    <target name="-post-package">
        <exec executable="androsign" failonerror="false" failifexecutionfails="false">
                <arg value="bin/test2-release-unsigned.apk"/>
        </exec>
        <!--copy file="bin/test2-release-unsigned-signed.apk" tofile="test2.apk"/-->
        <exec executable="cp" failonerror="false" failifexecutionfails="false">
                <arg value="bin/test2-release-unsigned-signed.apk"/>
                <arg value="test2.apk"/>
        </exec>

    </target>

</project>