Support bit-perfect PCM playback.

This is part of USB audio improvement. Bit-perfect PCM playback
indicates that the PCM data will be sent as is down to the audio HAL.
When the track is bit-perfect, there will not be volume control
applied in the audio mixer. Only effects without processing or hw
accelerated effects will be allowed to attach to bit-perfect tracks.

Bug: 239435816
Test: manually
Test: atest audiopolicy_tests
Change-Id: I0bad4d7d78d4eaf741754d01bc5422ba15374782
diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index 0f1373d..ebbdf56 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -83,7 +83,8 @@
                                   * ready as possible (aka. Buffer is full). */
                                 size_t frameCountToBeReady = SIZE_MAX,
                                 float speed = 1.0f,
-                                bool isSpatialized = false);
+                                bool isSpatialized = false,
+                                bool isBitPerfect = false);
     virtual             ~Track();
     virtual status_t    initCheck() const;
 
@@ -203,6 +204,7 @@
     audio_output_flags_t getOutputFlags() const { return mFlags; }
     float getSpeed() const { return mSpeed; }
     bool isSpatialized() const override { return mIsSpatialized; }
+    bool isBitPerfect() const override { return mIsBitPerfect; }
 
     /**
      * Updates the mute state and notifies the audio service. Call this only when holding player
@@ -361,6 +363,7 @@
     TeePatches  mTeePatches;
     const float         mSpeed;
     const bool          mIsSpatialized;
+    const bool          mIsBitPerfect;
 
     // TODO: replace PersistableBundle with own struct
     // access these two variables only when holding player thread lock.