DevTools: Update localization error message to warn about placeholder <ex>
DevTools: Update localization error message to warn about placeholder <ex>

The presubmit script did not warn about the missing example tag for placeholders.
This Cl added more details to the error message.
https://imgur.com/a/9I7hXfx

Bug: 941561
Change-Id: I2a950e4dd1fecc0a4dfea7467216c71c964c97b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1845580
Commit-Queue: Christy Chen <c65683e4a5ee30f610e160e4a73e5e01afd6eeda@microsoft.com>
Reviewed-by: Lorne Mitchell <b024a4e2ee56b9b5450225fa7affa8f95408a018@microsoft.com>
Reviewed-by: Mandy Chen <f3651d5e6e957857347d834049d3e79aaeabcca9@microsoft.com>
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#707569}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 21c1a43916ce6b405246e60c5c21613f372fdb68

ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend