Use btrfs for fedora/test-image-live-disk test

Change the Virtual profile to build a btrfs based image
for testing respective btrfs layouts

build-tests/x86/fedora/test-image-live-disk/appliance.kiwi

@@ -30,7 +30,12 @@
         </type>
     </preferences>
     <preferences profiles="Virtual">
-        <type image="oem" filesystem="ext4" kernelcmdline="console=ttyS0" firmware="uefi" format="qcow2">
+        <type image="oem" filesystem="btrfs" kernelcmdline="console=ttyS0" firmware="uefi" format="qcow2" btrfs_create_toplevel_subvolume="true" rootfs_label="fedora">
+            <systemdisk name="fedora">
+                <volume name="@root=root"/>
+                <volume name="home" mountpoint="/home" parent="/"/>
+                <volume name="machines" parent="/var/lib"/>
+            </systemdisk>
             <oemconfig>
                 <oem-resize>false</oem-resize>
             </oemconfig>
@@ -67,6 +72,7 @@
         <package name="vim"/>
         <package name="tzdata"/>
         <package name="NetworkManager"/>
+        <package name="btrfs-progs"/>
     </packages>
     <packages type="image" profiles="Live,Disk">
         <package name="syslinux"/>