[DevUI DFM] Update error message

Replacing "Something went wrong" with something that will suggest to
install the dev_ui module on developer builds, while keeping the
recommendations to get the module downloaded for official builds.

Bug: 1081812
Change-Id: I39949f85890bde349d4ce3d6801d861d51dfc2c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2196407
Commit-Queue: Egor Pasko <pasko@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770062}

ui/strings/ui_strings.grd

@@ -1134,7 +1134,7 @@ need to be translated for each locale.-->
       <if expr="is_android">
         <!-- DevUI DFM Loader error strings -->
         <message name="IDS_DEV_UI_LOADER_ERROR_HEADING" desc="Heading text for error page shown when Chrome fails to dynamically install the DevUI module.">
-          Something went wrong
+          Page load failed because the developer UI module (dev_ui) is not installed
         </message>
         <message name="IDS_DEV_UI_LOADER_ERROR_SUGGEST_RELOAD" desc="Suggests to reload page to retry install of the DevUI module.">
           Reloading this page