Merge changes I35a76a27,I04bb7ad4,If38a1a10,Ice5be6e5,I009e443f,I968ddf90,I69d4e518,I09b1dfc9

* changes:
  Merge commit '74803dc5'
  add config_bluetooth_default_profiles config var and use it to disable bt profiles
  Do not allow Surface creation on machines without SurfaceFlinger We will fail later anyways, but this change makes it much easier to track down places where we are inadvertently doing operations that depend on the flinger.
  fix setting only usb mode
  Detect (at runtime) kernel support for the "hdmi_audio" switch.
  Add a config resource to disable key-chord screenshotting
  Do not assume that there is always a running activity (Necessary for headless devices)
  Add batch volume adjust support to adjustMasterVolume() in AudioManager and AudioService.