Trying to use adobe air 17 in a Flex Mobile ap

hello,

My Flashbuilder is using  AIR 17 as is visible in AIR aps.

However, my Adobe flex mobile app won't let me update a certain line in the .xml

I want to change:

<?xml version="1.0" encoding="utf-8" standalone="no"?>

<application xmlns="http://ns.adobe.com/air/application/3.1">

to

<?xml version="1.0" encoding="utf-8" standalone="no"?>

<application xmlns="http://ns.adobe.com/air/application/17">

Yet when I try and debug, I get a popup window that says:

Process terminated without establishing connection to debugger.

invalid application descriptor: Unknown namespace: http://ns.adobe.com/air/application/17

Launch command details:  "C:\Program Files\Adobe\Adobe Flash Builder 4.7 (64 Bit)\sdks\4.6.0\bin\adl.exe" -runtime "C:\Program Files\Adobe\Adobe Flash Builder 4.7 (64 Bit)\sdks\4.6.0\runtimes\air\win" -profile mobileDevice -screensize 480x762:480x800 -XscreenDPI 252 -XversionPlatform AND "C:\Users\l\Adobe Flash Builder 4.7\CSemt\bin-debug\CSemt-app.xml" "C:\Users\l\Adobe Flash Builder 4.7\CSemt\bin-debug"

any help?