fix(demo): trim Android channel ID env var

Author: fadi-george

examples/demo/src/services/OneSignalApiService.ts

@@ -50,7 +50,7 @@ class OneSignalApiService {
         contents = { en: 'This notification plays a custom sound' };
         extra.ios_sound = 'vine_boom.wav';
         extra.android_channel_id =
-          ONESIGNAL_ANDROID_CHANNEL_ID ?? 'b3b015d9-c050-4042-8548-dcc34aa44aa4';
+          ONESIGNAL_ANDROID_CHANNEL_ID?.trim() || 'b3b015d9-c050-4042-8548-dcc34aa44aa4';
         break;
       default:
         return false;