Add bt_vendor_overlay.conf to gs201 folder

Add bt_vendor_overlay.conf for customizing project configuration
* If the overlay config has same config item with origin config, it
  will overwrite it.

Bug: 189727579
Test: build pass, Bluetooth can up successfully.
Change-Id: I48f160ab87b5d512b78884d4502c790587724cd9
2 files changed