[chromedriver] Improve log between Client and ChromeDriver

Do not truncate log for Command Send from client to ChromeDriver.

Bug: chromedriver:3541
Change-Id: Ia6588fb4ab5b35f0ff7295e348295b2d72aaf1d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2292870Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Shengfa Lin <shengfa@google.com>
Cr-Commit-Position: refs/heads/master@{#787386}

chrome/test/chromedriver/commands.cc

@@ -231,8 +231,7 @@ void ExecuteSessionCommandOnSessionThread(
       // Note: ChromeDriver log-replay depends on the format of this logging.
       // see chromedriver/log_replay/client_replay.py
       VLOG(0) << "[" << session->id << "] "
-              << "COMMAND " << command_name << " "
-              << FormatValueForDisplay(*params);
+              << "COMMAND " << command_name << " " << PrettyPrintValue(*params);
     }
   }