Disable output_sample.pcm

Update include files to include bt_target.h as it has the necessary
defines to correctly allow bdroid_buildcfg.h to enable and disable
dumping to output_sample.pcm.

Bug: 38180732
Test: Stream Bluetooth audio to device and observe that
output_sample.pcm does not get written or appended to.

Change-Id: Ia7926f93a47489686d315e3c9abd1618cb8adda3