LPS-137504 Preprocess HTML to remove freemarker variables

As long as the resulting HTML is valid, the replacement we use doesn't
really matter. Using a valid HTML identifier to avoid issues.

modules/apps/layout/layout-admin-web/src/main/java/com/liferay/layout/admin/web/internal/util/InfoFieldUtil.java

@@ -30,6 +30,8 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * @author Adolfo Pérez
@@ -54,7 +56,7 @@ public static <E extends Throwable> void forEachInfoField(
 		for (FragmentEntryLink fragmentEntryLink : fragmentEntryLinks) {
 			Map<String, String> editableTypes =
 				EditableFragmentEntryProcessorUtil.getEditableTypes(
-					fragmentEntryLink.getHtml());
+					_getHtml(fragmentEntryLink));
 
 			for (Map.Entry<String, String> entry : editableTypes.entrySet()) {
 				String type = entry.getValue();
@@ -74,6 +76,12 @@ public static <E extends Throwable> void forEachInfoField(
 		}
 	}
 
+	private static String _getHtml(FragmentEntryLink fragmentEntryLink) {
+		Matcher matcher = _pattern.matcher(fragmentEntryLink.getHtml());
+
+		return matcher.replaceAll("element");
+	}
+
 	private static InfoField<TextInfoFieldType> _getInfoField(
 		long fragmentEntryLinkId, String name, String type) {
 
@@ -107,4 +115,6 @@ private static boolean _isTextFieldType(String type) {
 		return false;
 	}
 
+	private static final Pattern _pattern = Pattern.compile("\\$\\{[^}]*\\}");
+
 }