Add useSystemProvidedLauncherForSecondary config

- Enabling this flag allows product to use the same secondary home launcher
  specified in config_secondaryHomeComponent always.
- In product like car, some secondary displays, only built-in secondary home
  launcher should be used.

Bug: 131112301
Test: Run added test

Change-Id: I8ec0c21685dacfeb142c34b1362586c15f87fe20