VtsHalTargetTest: Define kSamplingFrequency in EffectHelper.h

Bug: 305866207
Test: atest VtsHalVolumeTargetTest
      atest VtsHalPresetReverbTargetTest
      atest VtsHalVirtualizerTargetTest
      atest VtsHalBassBoostTargetTest
      atest VtsHalEnvironmentalReverbTargetTest

Change-Id: I922947094aead399ee652a7511b3e1dc8dd35a8c
diff --git a/audio/aidl/vts/EffectHelper.h b/audio/aidl/vts/EffectHelper.h
index 3877c60..f0622a8 100644
--- a/audio/aidl/vts/EffectHelper.h
+++ b/audio/aidl/vts/EffectHelper.h
@@ -84,6 +84,7 @@
 }
 
 static constexpr float kMaxAudioSampleValue = 1;
+static constexpr int kSamplingFrequency = 44100;
 
 class EffectHelper {
   public: