audio policy: fix gapless playback when effects enabled

Do not allow offloading if one non offloadable effect is enabled. This prevents from
creating an offloaded track and tearing it down immediately after start when audioflinger
detects there is an active non offloadable effect.
Not doing so breaks gapless playback because AwesomePlayer will always be able to open
an offloaded track which will not be compatible with the previous PCM track and
Audiosink::open() will not recycle it.

Bug: 11181933.
Change-Id: I6d163806849d9093b9ec701ba8e8c1ccb658e3c8
merge in klp-release (no-op)
Merge "audio policy: fix gapless playback when effects enabled" into klp-dev
Define and use DRC-specific volume curves when applicable

Add support for property defining whether a DRC on the speaker path
 is enabled and will boost soft sounds.
Define new volume curves with more attenuations than existing ones
 to compensate for DRC-induced boost on sonification sounds to
 provide a more "linear" control to the user over the applied volume.

Bug 11600699

Change-Id: If23dd097a8b9b5ebb61e75dd8512ff75e63ba899
Merge tag 'android-4.4.1_r1' into HEAD

Android 4.4.1 Release 1

Conflicts:
	audio/AudioPolicyManagerBase.cpp

Change-Id: I89ac037649e05540e85f7497e416f85032210776
audio: Disable sonification on digital USB outputs

 * We don't want to hear touch sounds on our badass USB DACs. Just
   play the damn music, please :)

Change-Id: I08b1c5d672d853fc7116c03cd77b8828881d3a5b
audio: fix offload enabling test parameter

passing NULL as the default to property_get doesn't return false,
it returns random memory junk that evaluates to true... Explicitly
default the state of this property to "false" as a default

Change-Id: Ib2808bf2540b2b4fdf754d489fb44aa5d9e061a8