add PromQL keyword for adhoc filter (#16426)

public/app/plugins/datasource/prometheus/add_label_to_query.ts

@@ -1,6 +1,6 @@
 import _ from 'lodash';
 
-const keywords = 'by|without|on|ignoring|group_left|group_right';
+const keywords = 'by|without|on|ignoring|group_left|group_right|bool|or|and|unless';
 
 // Duplicate from mode-prometheus.js, which can't be used in tests due to global ace not being loaded.
 const builtInWords = [