format-request-map: minor fixes and updates

- azure-rhui filename fix (.xz)
- azure-rhui doesn't need distro override
- minor formatting fixes

tools/test-case-generators/format-request-map.json

@@ -16,14 +16,9 @@
       "arch": "",
       "image-type": "azure-rhui",
       "repositories": [],
-      "filename": "disk.vhd",
+      "filename": "disk.vhd.xz",
       "blueprint": {}
     },
-    "overrides": {
-      "rhel-85": {
-        "distro": "rhel-86"
-      }
-    },
     "supported_arches": [
       "x86_64"
     ]
@@ -348,7 +343,7 @@
     },
     "no-image-info": true,
     "overrides": {}
-  },  
+  },
   "openstack": {
     "boot": {
       "type": "openstack"
@@ -558,7 +553,7 @@
     "no-image-info": true,
     "overrides": {
       "rhel-85": {
-        "blueprint":{
+        "blueprint": {
           "customizations": {
             "installation_device": "/dev/vda"
           }