Refactor VTS tests to use common sine input generation method

Bug: 305866207
Test: atest VtsHalVolumeTargetTest
      atest VtsHalPresetReverbTargetTest
      atest VtsHalVirtualizerTargetTest
      atest VtsHalBassBoostTargetTest
      atest VtsHalEnvironmentalReverbTargetTest
Change-Id: I6b31ba94ffed15b4ac467eec87e45c4c5f5b3805
diff --git a/audio/aidl/vts/EffectHelper.h b/audio/aidl/vts/EffectHelper.h
index f0622a8..d716975 100644
--- a/audio/aidl/vts/EffectHelper.h
+++ b/audio/aidl/vts/EffectHelper.h
@@ -429,19 +429,28 @@
         }
     }
 
-    // Generate multitone input between -1 to +1 using testFrequencies
-    void generateMultiTone(const std::vector<int>& testFrequencies, std::vector<float>& input,
-                           const int samplingFrequency) {
+    // Generate multitone input between -amplitude to +amplitude using testFrequencies
+    // All test frequencies are considered having the same amplitude
+    void generateSineWave(const std::vector<int>& testFrequencies, std::vector<float>& input,
+                          const float amplitude = 1.0,
+                          const int samplingFrequency = kSamplingFrequency) {
         for (size_t i = 0; i < input.size(); i++) {
             input[i] = 0;
 
             for (size_t j = 0; j < testFrequencies.size(); j++) {
                 input[i] += sin(2 * M_PI * testFrequencies[j] * i / samplingFrequency);
             }
-            input[i] /= testFrequencies.size();
+            input[i] *= amplitude / testFrequencies.size();
         }
     }
 
+    // Generate single tone input between -amplitude to +amplitude using testFrequency
+    void generateSineWave(const int testFrequency, std::vector<float>& input,
+                          const float amplitude = 1.0,
+                          const int samplingFrequency = kSamplingFrequency) {
+        generateSineWave(std::vector<int>{testFrequency}, input, amplitude, samplingFrequency);
+    }
+
     // Use FFT transform to convert the buffer to frequency domain
     // Compute its magnitude at binOffsets
     std::vector<float> calculateMagnitude(const std::vector<float>& buffer,