Unify Iron Coast mission names and cinematic mission previews

mods/aurora/content.json

@@ -121,6 +121,13 @@
     {
       "id": "aurora:field_trials",
       "name": "Aurora Field Trials",
+      "art": {
+        "png": "art/briefing_sd.png",
+        "hd_png": "art/briefing_hd.png",
+        "logical_width": 320,
+        "logical_height": 200,
+        "frames": 1
+      },
       "duration": 650,
       "spawns": [
         {