[DevTools] Fix copying PowerShell commands

Bug: 1004757
Change-Id: Ib3e3df302e6b8e995a767463a485ed29f6b511b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1825718Reviewed-by: Erik Luo <luoe@chromium.org>
Commit-Queue: Harley Li <hhli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700435}

third_party/blink/renderer/devtools/front_end/network/NetworkLogView.js

@@ -1322,7 +1322,7 @@ Network.NetworkLogView = class extends UI.VBox {
   }
 
   async _copyAllPowerShellCommand() {
-    const commands = this._generateAllPowerShellCommand(SDK.networkLog.requests());
+    const commands = await this._generateAllPowerShellCommand(SDK.networkLog.requests());
     InspectorFrontendHost.copyText(commands);
   }