usb: Add the boot completed check before broadcasting intent

Broadcasting intent is not allowed before boot completed.
Check if boot completed to broadcast accessory time out
intent to avoid exception.

Bug:229387375
Test: Reboot with head unit connected

Signed-off-by: Ricky Niu <rickyniu@google.com>
Change-Id: I34bc7625bbcb9525ad25cb1538ed4138fcae8ead