Add learn more to string resources

vector/src/main/java/im/vector/app/features/home/room/threads/ThreadsManager.kt

@@ -54,7 +54,8 @@ class ThreadsManager @Inject constructor(
      * Generates and return an Html spanned string to be rendered especially in dialogs
      */
     fun getBetaEnableThreadsMessage(): Spanned {
-        val href = "<a href='$learnMoreUrl'>Learn more</a>.<br><br>"
+        val learnMore = context.getString(R.string.action_learn_more)
+        val href = "<a href='$learnMoreUrl'>$learnMore</a>.<br><br>"
         val message = context.getString(R.string.threads_beta_enable_notice_message, href)
         return HtmlCompat.fromHtml(message, HtmlCompat.FROM_HTML_MODE_LEGACY)
     }

vector/src/main/res/values/strings.xml

@@ -385,6 +385,7 @@
     <string name="action_play">Play</string>
     <string name="action_dismiss">Dismiss</string>
     <string name="action_reset">Reset</string>
+    <string name="action_learn_more">Learn more</string>
 
     <string name="copied_to_clipboard">Copied to clipboard</string>