Minor improvements of task list

appengine/swarming/elements/res/imp/botlist/bot-list.html

Index: appengine/swarming/elements/res/imp/botlist/bot-list.html
diff --git a/appengine/swarming/elements/res/imp/botlist/bot-list.html b/appengine/swarming/elements/res/imp/botlist/bot-list.html
index 1813d0c88861608fbfe6a397959deb932ae3eb8e..b11a3bb9742771386e83a882ce98c3d67f3c9b9f 100644
--- a/appengine/swarming/elements/res/imp/botlist/bot-list.html
+++ b/appengine/swarming/elements/res/imp/botlist/bot-list.html
@@ -223,24 +223,26 @@
       // "id" and "task" are special, so they don't go here. They have their
       // headers hard-coded above.
       "android_devices": "Android Devices",
+      "battery_health": "Battery Health",
+      "battery_level": "Battery Level (%)",
+      "battery_status": "Battery Status",
+      "battery_temperature": "Battery Temp (°C)",
+      "battery_voltage": "Battery Voltage (mV)",
+      "bot_temperature": "Bot Temp (°C)",
       "cores": "Cores",
       "cpu": "CPU",
       "device": "Non-android Device",
       "device_os": "Device OS",
+      "device_temperature": "Device Temp (°C)",
       "device_type": "Device Type",
       "disk_space": "Free Space (MB)",
+      "first_seen": "First Seen",
       "gpu": "GPU",
+      "last_seen": "Last Seen",
       "os": "OS",
       "pool": "Pool",
       "status": "Status",
       "xcode_version": "XCode Version",
-      "battery_health": "Battery Health",
-      "battery_level": "Battery Level (%)",
-      "battery_status": "Battery Status",
-      "battery_temperature": "Battery Temp (°C)",
-      "battery_voltage": "Battery Voltage (mV)",
-      "bot_temperature": "Bot Temp (°C)",
-      "device_temperature": "Device Temp (°C)",
     };
 
     var columnMap = {