default browser check should run only on release build

fix brave#4958

Auditors: @bridiver, @bbondy

Test Plan:
1. Make sure there is no session data
2. npm run start/test should not popup the check default browser modal.
3. BRAVE_FORCE_CHECK_DEFAULT_ON_STARTUP=true npm run start/test
should popup the check default browser modal normally.

app/index.js

@@ -444,9 +444,14 @@ app.on('ready', () => {
  }
  process.emit(messages.APP_INITIALIZED)
 
- // Default browser checking
- let isDefaultBrowser = defaultProtocols.every(p => app.isDefaultProtocolClient(p))
- appActions.changeSetting(settings.IS_DEFAULT_BROWSER, isDefaultBrowser)
+ if (!process.env.BRAVE_FORCE_CHECK_DEFAULT_ON_STARTUP &&
+ ['development', 'test'].includes(process.env.NODE_ENV)) {
+ appActions.changeSetting(settings.IS_DEFAULT_BROWSER, true)
+ } else {
+ // Default browser checking
+ let isDefaultBrowser = defaultProtocols.every(p => app.isDefaultProtocolClient(p))
+ appActions.changeSetting(settings.IS_DEFAULT_BROWSER, isDefaultBrowser)
+ }
 
  if (CmdLine.newWindowURL) {
  appActions.newWindow(Immutable.fromJS({