[Telemetry] Update all WPR json files to the new format.

tools/perf/page_sets/data/maps.json

Index: tools/perf/page_sets/data/maps.json
diff --git a/tools/perf/page_sets/data/maps.json b/tools/perf/page_sets/data/maps.json
index c84140ebab1acb557971e236284c126673eb5f5a..09d0d3ec770ca56af13fa209d808d432302f98f3 100644
--- a/tools/perf/page_sets/data/maps.json
+++ b/tools/perf/page_sets/data/maps.json
@@ -1,11 +1,12 @@
 {
-    "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating.", 
     "archives": {
-        "maps_002.wpr": [
-            "http://localhost:10020/tracker.html"
-        ], 
-        "maps_004.wpr": [
-            "http://localhost:8000/performance.html"
-        ]
-    }
+        "http://localhost:10020/tracker.html": {
+            "DEFAULT": "maps_002.wpr"
+        },
+        "http://localhost:8000/performance.html": {
+            "DEFAULT": "maps_004.wpr"
+        }
+    },
+    "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating.",
+    "platform_specific": true
 }