add avvolumepanel defination

Signed-off-by: cheng <chengcheng14@huawei.com>

api/@ohos.multimedia.avVolumePanel.d.ets

@@ -0,0 +1,70 @@
+/*
+* Copyright (C) 2024 Huawei Device Co., Ltd.
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+/**
+ * @file Defines a panel to set the system audio output volume.
+ * @kit AudioKit
+ */
+
+/**
+ * Declare custom parameters used for volume panel.
+ *
+ * @syscap SystemCapability.Multimedia.Audio.Volume
+ * @atomicservice
+ * @since 12
+ */
+export declare class AVVolumePanelParameter {
+  /**
+   * Sets the position of volume panel.
+   *
+   * @syscap SystemCapability.Multimedia.Audio.Volume
+   * @atomicservice
+   * @since 12
+   */
+  position?: Position;
+}
+
+/**
+ * A panel to set the system audio output volume.
+ *
+ * @syscap SystemCapability.Multimedia.Audio.Volume
+ * @atomicservice
+ * @since 12
+ */
+@Component
+export declare struct AVVolumePanel {
+  /**
+   * Sets the device volume through the volume panel.
+   * The value should be between mininum and maxinum current device volume, otherwise it will be discarded.
+   *
+   * @type { ?number }
+   * @syscap SystemCapability.Multimedia.Audio.Volume
+   * @atomicservice
+   * @since 12
+   */
+  @Prop
+  volumeLevel?: number;
+
+  /**
+   * Sets the custom parameters of volume panel.
+   *
+   * @type { ?AVVolumePanelParameter }
+   * @syscap SystemCapability.Multimedia.Audio.Volume
+   * @atomicservice
+   * @since 12
+   */
+  @Prop
+  volumeParameter?: AVVolumePanelParameter;
+}