Fix French install test on aarch64 by skipping `uefi_postinstall`

The French install/boot test fails on aarch64 due to a bit of an
ordering issue:

https://openqa.stg.fedoraproject.org/tests/665124

we run `uefi_postinstall`, which does `loadkeys us`, before we
run `_console_login`, which still expects the French layout, so
it breaks. The safest way to solve this I think is to add a new
variable that lets us skip `uefi_postinstall` - I don't want to
change the ordering so we load `uefi_postinstall` after we read
`POSTINSTALL` in case that breaks things somewhere else.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

VARIABLES.md

@@ -79,6 +79,7 @@ it also means that `B` conflicts `A` even if not shown in the table).
 | `ANACONDA_TEXT` | boolean | `false`/not set | all | when specified, anaconda will run in text mode |
 | `ANACONDA_STATIC` | string (IPv4 address) | not set | `ANACONDA_TEXT` | If set, will set up static networking using the chosen IP address during install |
 | `POST_STATIC` | string (space-separated IPv4 address and hostname) | not set | nothing | If set, will set up static networking using the chosen IP address and hostname during early post-install |
+| `NO_UEFI_POST` | boolean | `false`/not set | nothing | If set, `uefi_postinstall` test will not be loaded even if `UEFI` is set (can be useful for non-English tests to avoid `uefi_postinstall` running loadkeys) |
 
 Run variables
 -------------

main.pm

@@ -298,7 +298,7 @@ sub load_postinstall_tests() {
     }
     autotest::loadtest $storagepost if ($storagepost);
 
-    if (get_var("UEFI")) {
+    if (get_var("UEFI") &! get_var("NO_UEFI_POST")) {
         autotest::loadtest "tests/uefi_postinstall.pm";
     }
 

templates

@@ -5177,6 +5177,7 @@
                         { key => "REPOSITORY_VARIATION", value => "%LOCATION%" },
                         { key => "HDDSIZEGB", value => "13" },
                         { key => "QEMU_DISABLE_SNAPSHOTS", value => "1" },
+                        { key => "NO_UEFI_POST", value => "1" },
                       ],
                     },
                     {