floss: avrcp: uinput: add (AVRCP) suffix to the uinput device

Follow BlueZ's naming convention, adding a "(AVRCP)" suffix to the
input device name, which helps the existing test locate the uinput
device.


Bug: 259144894
Tag: #floss
Test: bluetooth_AdapterAUHealth.au_avrcp_command_test.floss

Change-Id: I2f0668313e6c724a961e2fc79b78ab6d30eaca53