Fix code scanning alert no. 6: Incomplete string escaping or encoding

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
(cherry picked from commit 372444c)

src/app/core/shared/metadata.utils.ts

@@ -163,7 +163,7 @@ export class Metadata {
     const outputKeys: string[] = [];
     for (const inputKey of inputKeys) {
       if (inputKey.includes('*')) {
-        const inputKeyRegex = new RegExp('^' + inputKey.replace(/\./g, '\\.').replace(/\*/g, '.*') + '$');
+        const inputKeyRegex = new RegExp('^' + inputKey.replace(/\\/g, '\\\\').replace(/\./g, '\\.').replace(/\*/g, '.*') + '$');
         for (const mapKey of Object.keys(mdMap)) {
           if (!outputKeys.includes(mapKey) && inputKeyRegex.test(mapKey)) {
             outputKeys.push(mapKey);