Layouts: Use double-quotes more consistently

Part-of: <https://gitlab.gnome.org/World/Phosh/squeekboard/-/merge_requests/643>

data/keyboards/terminal/es.yaml

@@ -62,7 +62,7 @@ buttons:
     BackSpace:
         outline: "altline"
         icon: "edit-clear-symbolic"
-        action: erase
+        action: "erase"
     preferences:
         action: "show_prefs"
         outline: "special"
@@ -99,7 +99,7 @@ buttons:
             set_view: "actions"
         outline: "change-view"
         label: ">_"
-    ".":
+    .:
         outline: "large"
         text: "."
     space: