Modify AVTransportSerivce

1 Return StorageMedium.NETWORK in getDeviceCapabilities.
2 Set PlayModie.Normal in getTransportSettings.

Signed-off-by: FuXi Chu <fuxi.chu@archermind.com>
Modify AVTransportService

1 Add state switching info in getCurrentTransportActions

Signed-off-by: FuXi Chu <fuxi.chu@archermind.com>