Add Multi-tab System Health Story

tools/perf/page_sets/data/system_health_desktop.json

Index: tools/perf/page_sets/data/system_health_desktop.json
diff --git a/tools/perf/page_sets/data/system_health_desktop.json b/tools/perf/page_sets/data/system_health_desktop.json
index 35f5945ef325e19205980258f2bd2d6a0b9afbfc..a542d446740357e9717fa16cfabb0763ba0db5ab 100644
--- a/tools/perf/page_sets/data/system_health_desktop.json
+++ b/tools/perf/page_sets/data/system_health_desktop.json
@@ -171,6 +171,9 @@
         "long_running:tools:gmail-foreground": {
             "DEFAULT": "system_health_desktop_028.wpr"
         },
+        "multitab:misc:typical24": {
+            "DEFAULT": "system_health_desktop_048.wpr"
+        },
         "play:media:google_play_music": {
             "DEFAULT": "system_health_desktop_030.wpr"
         },
@@ -186,4 +189,4 @@
     },
     "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating.",
     "platform_specific": true
-}
+}