Kerberos: Make tickets forwardable by default

Tickets should be forwardable by default to match the behavior for
Chromad. This was an oversight.

BUG=None
TEST=Tested manually that getting tickets still works

Change-Id: If35ba1d73e4348c3d87f6a685d509c24bdf5f621
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1753929Reviewed-by: Lutz Justen <ljusten@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Auto-Submit: Lutz Justen <ljusten@chromium.org>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688686}

chrome/browser/chromeos/kerberos/kerberos_credentials_manager.cc

@@ -55,7 +55,8 @@ constexpr char kLoginPasswordPlaceholder[] = "${PASSWORD}";
 constexpr char kDefaultKerberosConfig[] = R"([libdefaults]
   default_tgs_enctypes = aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96
   default_tkt_enctypes = aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96
-  permitted_enctypes = aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96)";
+  permitted_enctypes = aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96
+  forwardable = true)";
 
 // If |principal_name| is "UsEr@realm.com", sets |principal_name| to
 // "user@REALM.COM". Returns false if the given name has no @ or one of the