use custom key to encript mmkv storage

__mocks__/react-native-mmkv-storage.js

@@ -5,7 +5,7 @@ export class MMKVLoader {
 
 	setProcessingMode = jest.fn().mockImplementation(() => ({
 		withEncryption: jest.fn().mockImplementation(() => ({
-			initialize: jest.fn().mockImplementation(() => {})
+			encryptWithCustomKey: jest.fn().mockImplementation(() => ({ initialize: jest.fn().mockImplementation(() => {}) }))
 		}))
 	}));
 }

app/lib/methods/userPreferences.ts

@@ -4,6 +4,7 @@ const MMKV = new MMKVLoader()
 	// MODES.MULTI_PROCESS = ACCESSIBLE BY APP GROUP (iOS)
 	.setProcessingMode(ProcessingModes.MULTI_PROCESS)
 	.withEncryption()
+	.encryptWithCustomKey('rocket-chat') // JUST A TEST KEY
 	.initialize();
 
 export const useUserPreferences = create(MMKV);