Build fix - add sHearingAidVolumeCurve definition in Gains.h

Test: compilation
Bug: 69623109
Change-Id: I021834d8013eced600c669b1be3f08721fd35092
diff --git a/services/audiopolicy/common/managerdefinitions/include/Gains.h b/services/audiopolicy/common/managerdefinitions/include/Gains.h
index 8332af9..cb229a4 100644
--- a/services/audiopolicy/common/managerdefinitions/include/Gains.h
+++ b/services/audiopolicy/common/managerdefinitions/include/Gains.h
@@ -52,6 +52,7 @@
     static const VolumeCurvePoint sLinearVolumeCurve[Volume::VOLCNT];
     static const VolumeCurvePoint sSilentVolumeCurve[Volume::VOLCNT];
     static const VolumeCurvePoint sFullScaleVolumeCurve[Volume::VOLCNT];
+    static const VolumeCurvePoint sHearingAidVolumeCurve[Volume::VOLCNT];
     // default volume curves per stream and device category. See initializeVolumeCurves()
     static const VolumeCurvePoint *sVolumeProfiles[AUDIO_STREAM_CNT][DEVICE_CATEGORY_CNT];
 };