[system-health] Rename browse:media:facebook to browse:media:facebook_photos

tools/perf/page_sets/data/system_health_mobile.json

 {
     "archives": {
         "system_health_mobile_000.wpr": [
             "load:search:amazon",
             "load:search:baidu",
             "load:search:yandex",
             "load:search:taobao",
             "load:search:ebay",
             "load:search:yahoo"
         ],
@@ skipping 25 matching lines @@
             "load:tools:docs"
         ],
         "system_health_mobile_005.wpr": [
             "load:games:lazors",
             "load:games:bubbles",
             "load:games:spychase"
         ],
         "system_health_mobile_006.wpr": [
             "load:news:cnn"
         ],
-        "system_health_mobile_007.wpr": [
-            "load:social:facebook"
-        ],
         "system_health_mobile_008.wpr": [
             "load:news:hackernews"
         ],
         "system_health_mobile_009.wpr": [
             "load:news:nytimes"
         ],
         "system_health_mobile_010.wpr": [
             "load:news:qq"
         ],
         "system_health_mobile_011.wpr": [
@@ skipping 26 matching lines @@
         "system_health_mobile_024.wpr": [
             "load:news:flipboard"
         ],
         "system_health_mobile_025.wpr": [
             "browse:news:flipboard"
         ],
         "system_health_mobile_027.wpr": [
             "browse:news:reddit"
         ],
         "system_health_mobile_028.wpr": [
+            "load:social:facebook",
             "browse:social:facebook"
         ],
         "system_health_mobile_029.wpr": [
             "load:search:google",
             "search:portal:google"
         ],
         "system_health_mobile_035.wpr": [
             "browse:media:imgur",
             "load:media:imgur"
         ],
         "system_health_mobile_037.wpr": [
             "browse:media:youtube"
         ],
         "system_health_mobile_040.wpr": [
-            "browse:media:facebook"
+            "load:media:facebook_photos",
+            "browse:media:facebook_photos"
         ]
     },
     "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating."
 }