Bug 1370645 - Fix sync notification message following platform conventions r=eoger

MozReview-Commit-ID: HjJuH4peSxE

--HG--
extra : rebase_source : 790c5349507091e61c7d8345c203119d50ff2276

browser/locales/en-US/chrome/browser/accounts.properties

@@ -26,7 +26,7 @@ deviceConnectedBody.noDeviceName = This computer is now syncing with a new devic
 
 # LOCALIZATION NOTE (syncStartNotification.title, syncStartNotification.body)
 # These strings are used in a notification shown after Sync is connected.
-syncStartNotification.title = Sync enabled
+syncStartNotification.title = Sync Enabled
 # %S is brandShortName
 syncStartNotification.body2 = %S will begin syncing momentarily.