floss: pandora: Allows multiple advertisement in host.Advertise

In the current implementation, we incorrectly allow only
one advertisement on the Pandora server.

Bug: 326336280
Tag: #floss
Test: m Bluetooth
Test: pts-bot GATT/SR/GAC/BV-01-C
Flag: EXEMPT floss only changes
Change-Id: I9fb7ac2466f59baa65a86a3edd7ce4e8e2f8fbf3