Change Crostini Settings row label to "Linux"

Change-Id: I3404f7d9d99b3e2636ab3e5cc3e0c5850975bf39
Reviewed-on: https://chromium-review.googlesource.com/1159935Reviewed-by: Nicholas Verne <nverne@chromium.org>
Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Renée Wright <rjwright@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580383}

chrome/app/settings_strings.grdp

@@ -435,7 +435,7 @@
       Linux (Beta)
     </message>
     <message name="IDS_SETTINGS_CROSTINI_LABEL" desc="The text associated with the primary section setting.">
-      Linux (Beta)
+      Linux
     </message>
     <message name="IDS_SETTINGS_CROSTINI_SUBTEXT" desc="Description for the section for enabling and managing Crostini.">
       Run Linux tools, editors, and IDEs on your Chromebook.