Change scope of grub2_bootloader_argument templated tests

Some test scenarios test correct handling of *values* of bootloader
arguments. But, not all arguments have values, some arguments are
value-less, for example `nousb`. For the value-less arguments it
doesn't make sense to test the correct handling of values. Some
tests that currently attempt to do this are broken.

We will fix it by disabling the test scenarios.
We will use the well-known "trick" of setting the `# platform`
header to `Not Applicable` if the bootloader argument isn't supposed
to have any value. These are rules where the template isn't given
the `arg_value` or `arg_variable` parameter.

Fixes failing templated test scenario `wrong_value_entries.fail.sh`
in rule `grub2_nousb_argument`.

Author: jan-cerny

shared/templates/grub2_bootloader_argument/tests/wrong_value_entries.fail.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
+{{% if not ARG_VALUE and not ARG_VARIABLE %}}
+# platform = Not Applicable
+{{% else %}}
 # platform = multi_platform_fedora,multi_platform_rhel
+{{% endif %}}
 # packages = grub2,grubby
 
 {{%- if ARG_VARIABLE %}}

shared/templates/grub2_bootloader_argument/tests/wrong_value_etcdefault.fail.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
+{{% if not ARG_VALUE and not ARG_VARIABLE %}}
+# platform = Not Applicable
+{{% else %}}
 # platform = multi_platform_all
+{{% endif %}}
 
 {{%- if 'ubuntu' in product %}}
 # packages = grub2

shared/templates/grub2_bootloader_argument/tests/wrong_value_etcdefault_dir.fail.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
+{{% if not ARG_VALUE and not ARG_VARIABLE %}}
+# platform = Not Applicable
+{{% else %}}
 # platform = multi_platform_ubuntu
+{{% endif %}}
 # packages = grub2
 
 {{%- if ARG_VARIABLE %}}

shared/templates/grub2_bootloader_argument/tests/wrong_value_etcdefaultgrub_recovery_disabled.fail.sh

@@ -1,5 +1,10 @@
 #!/bin/bash
+
+{{% if not ARG_VALUE and not ARG_VARIABLE %}}
+# platform = Not Applicable
+{{% else %}}
 # platform = multi_platform_all
+{{% endif %}}
 
 {{%- if ARG_VARIABLE %}}
 # variables = {{{ ARG_VARIABLE }}}={{{ TEST_VALUE_PASS }}}

shared/templates/grub2_bootloader_argument/tests/wrong_value_grubenv.fail.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
+{{% if not ARG_VALUE and not ARG_VARIABLE %}}
+# platform = Not Applicable
+{{% else %}}
 # platform = Oracle Linux 8,Red Hat Enterprise Linux 8
+{{% endif %}}
 # packages = grub2,grubby
 
 {{%- if ARG_VARIABLE %}}