Make My DeviceAdminReceiver Removable

I'm writing a xamarin app for android that uses the device admin api to implement a "kiosk mode". To do this I've implemented a subclass of DeviceAdminReceiver and and set that component as a device administrator via the adb command " dpm set-device-owner ". I am able to do this successfully.

However, after I've made the application a device administrator I'm unable to remove the application without doing a factory wipe which is making debugging a real pita. The dpm command help output says that you can use the remove_active_admin subcommand to remove a device admin if android:testOnly is declared in the app manifest. I attempted to do this via the Application attribute in e.g.

[Application(Debuggable = true, TestOnly = true )]
public class MyApp: Application
{
}

However the TestOnly propery is not available on the application attribute in xamarin.

My questions are ...

1. How do I add the testOnly property to my manifest in xamarin?
2. Is this there another way to make my DeviceAdminReceiver removable?

Below are screenshots from the Settings -> Security -> Device Administrator menu.

1. Shows my DeviceAdminReceiver successfully activated.
2. Shows the remove option greyed out for my DeviceAdminReceiver.
3. Shows a different DeviceAdminReceiver on my device with the option to remove enabled.

Thanks!

Update

Many thanks to SushiHangover for the answer. I wanted to add that if you set this flag in your manifest, the apk will no longer install properly when you debug the project. Instead you'll have to use the adb pm command to install the package. I made the following scripts to simplify installing / removing the apk. Side note the dpm command fails for me if the root namespace starts with a capital letter.

To install

adb push com.bla.myproject.apk /sdcard/app.apk
adb shell pm install -t /sdcard/app.apk
adb shell dpm set-device-owner com.bla.myproject/com.bla.myproject.AdminRx

To remove

adb shell dpm remove-active-admin com.bla.myproject/com.bla.myproject.AdminRx
adb shell pm uninstall com.bla.myproject

Just edit and add it manually to the existing manifest in the Properties folders of your project:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.sushihangover.Android_BottomBar">
    <uses-sdk android:minSdkVersion="16" />
    <application android:testOnly="true" android:label="@string/app_name" android:theme="@android:style/Theme.Holo.Light.DarkActionBar">
    </application>
</manifest>

Along with your ApplicationAtrributes:

#if DEBUG
    [Application(Debuggable = true, AllowBackup = false, Icon = "@mipmap/icon_debug")]
#else
    [Application(Debuggable = false, AllowBackup = true, Icon = "@mipmap/icon")]
#endif
    public class App : Application
    {
       ~~~

They will both get merged together during the build process and become:

~~~
<application android:testOnly="true" android:label="@string/app_name" android:theme="@android:style/Theme.Holo.Light.DarkActionBar" android:allowBackup="false" android:debuggable="true" android:icon="@mipmap/icon_debug" android:name="md59b195add2a2dc8f3ae98a691cd945df5.App">
    ~~~
</application>
~~~