Pass kernel cmdline to agama

In the agama integration test make sure to pass along
the kernel boot parameters to allow controlling the
behavior of agama better

build-tests/x86/tumbleweed/test-image-agama/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" fsmountoptions="compress=zstd:15" firmware="uefi" installiso="true" installpxe="true" installboot="install" kernelcmdline="rd.kiwi.ramdisk ramdisk_size=2097152" volid="agama">
+        <type image="oem" filesystem="btrfs" fsmountoptions="compress=zstd:15" firmware="uefi" installiso="true" installpxe="true" installboot="install" kernelcmdline="rd.kiwi.ramdisk ramdisk_size=2097152 rd.kiwi.install.pass.bootparam" volid="agama">
             <bootloader name="grub2" timeout="1"/>
             <oemconfig>
                 <oem-skip-verify>true</oem-skip-verify>