Add customAgent beta constant

Add CUSTOM_AGENT: 'customAgent' to the BETAS object in CONST

Co-authored-by: Abdelhafidh Belalia <s77rt@users.noreply.github.com>

Author: MelvinBot

src/CONST/index.ts

@@ -869,6 +869,7 @@ const CONST = {
         ALL: 'all',
         ASAP_SUBMIT: 'asapSubmit',
         CSV_CARD_IMPORT: 'csvCardImport',
+        CUSTOM_AGENT: 'customAgent',
         DEFAULT_ROOMS: 'defaultRooms',
         PREVENT_SPOTNANA_TRAVEL: 'preventSpotnanaTravel',
         REPORT_FIELDS_FEATURE: 'reportFieldsFeature',