Clarify API doc for BluetoothGattServer::addService

Clarify that the caller has to wait for onServiceAdded callback before
calling BluetoothGattServer::addService again.

Bug: 72717069
Test: Compile
Change-Id: I20b031c724ba64bfd71cf10e58e587f69e4a2555
1 file changed
tree: b48c06ce158e88a91a4acc06247939e293e20714
  1. framework/
  2. service/