APC: Disable MMAP when a stream is to be captured

As MMAP does not support APC, it is disabled when a render loopback
policy is installed.

Test: adb shell write_sine_callback -pl # mmap is used
      adb shell audiorecorder  --target /data/file1.raw &
      adb shell write_sine_callback -pl # mmap is NOT used
Change-Id: Ia90c24953890de7e19fd99485bf760788f81126d
Signed-off-by: Kevin Rocard <krocard@google.com>