Bug 1496180 - Add security devices description and correct error parsing. r=flod,Felipe

Differential Revision: https://phabricator.services.mozilla.com/D7747

--HG--
extra : moz-landing-system : lando

browser/components/enterprisepolicies/Policies.jsm

@@ -765,7 +765,7 @@ var Policies = {
           try {
             pkcs11.addModule(deviceName, securityDevices[deviceName], 0, 0);
           } catch (ex) {
-            log.error("Unable to add security device ${deviceName}");
+            log.error(`Unable to add security device ${deviceName}`);
             log.debug(ex);
           }
         }

browser/locales/en-US/browser/policies/policies-descriptions.ftl

@@ -110,6 +110,9 @@ policy-SearchBar = Set the default location of the search bar. The user is still
 
 policy-SearchEngines = Configure search engine settings. This policy is only available on the Extended Support Release (ESR) version.
 
+# For more information, see https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/PKCS11/Module_Installation
+policy-SecurityDevices = Install PKCS #11 modules.
+
 # “format” refers to the format used for the value of this policy. See also:
 # https://github.com/mozilla/policy-templates/blob/master/README.md#websitefilter-machine-only
 policy-WebsiteFilter = Block websites from being visited. See documentation for more details on the format.