[ios] Remove string limit for the incognito badge string

The translation team had a hard time limiting it to 15 characters,
and it really shouldn't have a limit.

Bug: 976901
Change-Id: I14af6189954c7813c3e7e9a738b4458f47f89455
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1804456Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697273}

ios/chrome/app/strings/ios_strings.grd

@@ -311,7 +311,7 @@ locale.  The strings in this file are specific to iOS.
       <message name="IDS_IOS_AUTOFILL_ZIP" desc="Title of the field of a profile address representing the postal code of the address. [Length: 15em] [iOS only]">
         Zip Code
       </message>
-      <message name="IDS_IOS_BADGE_INCOGNITO_HINT" desc="Button displayed when the user is in Incognito mode [Length: 15 em] [iOS only]">
+      <message name="IDS_IOS_BADGE_INCOGNITO_HINT" desc="Button displayed when the user is in Incognito mode. [iOS only]">
         Current Webpage is on Incognito
       </message>
       <message name="IDS_IOS_BANDWIDTH_MANAGEMENT_LEARN_URL" translateable="false">