Remove logcats from instrumentation test run steps.

scripts/slave/recipes/chromium.expected/dynamic_instrumentation_test.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.linux",
       "--builder",
       "Android Tests",
@@ skipping 503 matching lines @@
     "cwd": "[SLAVE_BUILD]",
     "name": "spawn_device_monitor"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/out/Release/bin/run_chrome_public_test_apk",
       "--blacklist-file",
       "[SLAVE_BUILD]/src/out/bad_devices.json",
-      "--logcat-output-file",
-      "/path/to/tmp/",
       "--flakiness-dashboard-server",
       "test-results.appspot.com",
       "--verbose",
       "--json-results-file",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "Instrumentation test ChromePublicTest",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br/>failures:<br/>TestB<br/>@@@"
@@ skipping 255 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]