UsbMidiDevice: fix MIDI flush()

The proxy MidiReceiver in the USB device was not forwarding the flush
command to the event scheduler.

Bug: 25511696
Change-Id: I6a4759b71bc8f9ae3e20aed1238f62a2ed405e24
Signed-off-by: Phil Burk <philburk@google.com>
1 file changed