MDL-67115 google: php74 params order for implode()

Passing parameters to implode() in reverse order is deprecated, use
implode($glue, $parts) instead of implode($parts, $glue).

This commit corresponds to general search of wrong cases.

lib/google/readme_moodle.txt

@@ -38,6 +38,8 @@ Here are the files that we have added.
 
 Local changes (to reapply until upstream upgrades contain them):
     * MDL-67034 php74 compliance fixes
+    * MDL-67115 php74 implode() compliance fixes. This is fixed in upstream library v2.2.4
+      (verify that https://github.com/googleapis/google-api-php-client/pull/1683 is applied)
 
 
 Information

lib/google/src/Google/Http/REST.php

@@ -170,7 +170,7 @@ class Google_Http_REST
     }
 
     if (count($queryVars)) {
-      $requestUrl .= '?' . implode($queryVars, '&');
+      $requestUrl .= '?' . implode('&', $queryVars);
     }
 
     return $requestUrl;