floss: avrcp: connect bluetooth_media with uinput

Connect AVRCP connect/disconnect event to uinput to create and close
uinput device with the kernel. Then, route key event to uinput to have
AVRCP commands taking effect.

Explicitly connect to AVRCP profile with media interface through
topshim when connect/disconnect initiated by the host.

Bug: 240780817
Tag: #floss
Test: AVRCP is working!
Change-Id: I040a6d81882dfdca28216011f1872b13dd87b3b3