Telemetry: Clean up tap and click_element gestures.

tools/perf/page_sets/key_silk_cases.json

 {
   "description": "Pages hand-picked for project Silk.",
   "archive_data_file": "data/key_silk_cases.json",
   "credentials_path": "data/credentials.json",
   "user_agent_type": "mobile",
   "smoothness": { "action": "scroll" },
   "navigate_steps" : [
     { "action": "navigate" },
     { "action": "wait", "seconds": 2 }
   ],
@@ skipping 141 matching lines @@
       "navigate_steps" : [
         { "action": "navigate" },
         { "action": "wait", "seconds": 2 }
       ],
       "smoothness": {
         "action": "toggle_drawer",
         "repeat": 6
       },
       "toggle_drawer": [
         {
-          "action": "click_element",
-          "selector": "#menu-button"
-        },
-        { "action": "wait", "seconds": 1 }
+          "action": "tap",
+          "selector": "#menu-button",
+          "wait_after": { "seconds": 1 }
+        }
       ]
     },
     {
       "url": "file://key_silk_cases/old_inbox_app.html?slide_drawer",
       "why": "",
       "navigate_steps" : [
         { "action": "navigate" },
         { "action": "wait", "seconds": 2 }
       ],
       "smoothness": {
@@ skipping 106 matching lines @@
         { "action": "wait", "javascript": "document.getElementsByClassName('tweet').length > 0" },
         { "action": "wait", "seconds": 1 }
       ],
       "smoothness": {
         "action": "scroll",
         "scroll_distance_function": "function() { return 5000; }"
       }
     }
   ]
 }