Deprecate ditherAndClamp with memcpy_to_i16_from_q4_27

Test: test-mixer and SoloTester
Bug: 69636805
Change-Id: I5cc04d82f3e46fbfc8188a63eb2a90fb70634c90
diff --git a/media/libaudioprocessing/AudioMixer.cpp b/media/libaudioprocessing/AudioMixer.cpp
index 3e72c89..43b97a5 100644
--- a/media/libaudioprocessing/AudioMixer.cpp
+++ b/media/libaudioprocessing/AudioMixer.cpp
@@ -1947,11 +1947,10 @@
     case AUDIO_FORMAT_PCM_16_BIT:
         switch (mixerOutFormat) {
         case AUDIO_FORMAT_PCM_FLOAT:
-            memcpy_to_float_from_q4_27((float*)out, (int32_t*)in, sampleCount);
+            memcpy_to_float_from_q4_27((float*)out, (const int32_t*)in, sampleCount);
             break;
         case AUDIO_FORMAT_PCM_16_BIT:
-            // two int16_t are produced per iteration
-            ditherAndClamp((int32_t*)out, (int32_t*)in, sampleCount >> 1);
+            memcpy_to_i16_from_q4_27((int16_t*)out, (const int32_t*)in, sampleCount);
             break;
         default:
             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);