Update leap test-image-disk integration test

Add test for alternative volume ID in install ISO

Author: schaefi

build-tests/x86/leap/test-image-disk/appliance.kiwi

@@ -16,7 +16,7 @@
         <rpm-check-signatures>false</rpm-check-signatures>
         <bootsplash-theme>bgrt</bootsplash-theme>
         <bootloader-theme>openSUSE</bootloader-theme>
-        <type image="oem" filesystem="btrfs" kernelcmdline="console=ttyS0" firmware="efi" installiso="true" bootpartition="false" installboot="install">
+        <type image="oem" filesystem="btrfs" kernelcmdline="console=ttyS0" firmware="efi" installiso="true" bootpartition="false" installboot="install" volid="KATO_INSTALL">
             <bootloader name="grub2" console="serial" timeout="10"/>
             <oemconfig>
                 <oem-unattended>true</oem-unattended>