[AOA FFS Implementation] Adding support for accessory mode requests.

This change adds support for USB accessory mode control requests.
Specifically the requests for:
- GETPROTOCOL
- SENDSTRING
- START
These requests are used to negotiate and establish a connection using
USB Accessory mode. The negotiation information is stored in the vendor
control request monitor to be fetched when requested by clients later.

Bug: 407985367
Bug: 421809234
Flag: android.hardware.usb.flags.enable_aoa_userspace_implementation
Test: No breakage
Change-Id: I7d3a14166a139bf09c394755c3b056c0cf89699c