All added Volume profile override removed on resetting along with following errors:
-AddAssetToSameFile failed because the other asset VolumeProfile is not persistent
-UnityException: Adding asset to object VolumeProfile failed.
-NullReferenceException: Object reference not set to an instance of object errors are thrown continuously.

Steps to repro:
1. Create a new HDRP project
2. Project view > Right-Click > Create > Volume Profile.
3. Create its preset asset > Select VolumeProfile Preset.
4. Add Exposure Overrides > Reset "Exposure Overrides".

Actual Result:
Volume profile override removes on resetting with errors in the console.

Expected Result:
Volume profile override should be reset without any errors.

Reproducible in:
2020.2.0a9, 2020.1.0b8, 2020.1.0a23 with Package Version 9.0.0, 8.1.0, 8.0.1.

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
AddAssetToSameFile failed because the other asset VolumeProfile is not persistent
UnityEditor.GenericMenu:CatchMenu (object,string[],int)

UnityException: Adding asset to object VolumeProfile failed.
UnityEditor.AssetDatabase.AddObjectToAsset (UnityEngine.Object objectToAdd, UnityEngine.Object assetObject) (at <5951c2421c324f47883bd5ba8a4bf507>:0)
UnityEditor.Rendering.VolumeComponentListEditor.ResetComponent (System.Type type, System.Int32 id) (at Library/PackageCache/com.unity.render-pipelines.core@9.0.0-preview.13/Editor/Volume/VolumeComponentListEditor.cs:385)
UnityEditor.Rendering.VolumeComponentListEditor+<>c__DisplayClass16_0.<OnContextClick>b__2 () (at Library/PackageCache/com.unity.render-pipelines.core@9.0.0-preview.13/Editor/Volume/VolumeComponentListEditor.cs:267)
UnityEditor.GenericMenu.CatchMenu (System.Object userData, System.String[] options, System.Int32 selected) (at <5951c2421c324f47883bd5ba8a4bf507>:0)

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Rendering.VolumeComponentListEditor.OnGUI () (at Library/PackageCache/com.unity.render-pipelines.core@9.0.0-preview.13/Editor/Volume/VolumeComponentListEditor.cs:213)
UnityEditor.Rendering.VolumeProfileEditor.OnInspectorGUI () (at Library/PackageCache/com.unity.render-pipelines.core@9.0.0-preview.13/Editor/Volume/VolumeProfileEditor.cs:25)
UnityEditor.Presets.PresetEditor.DrawInternalInspector () (at <5951c2421c324f47883bd5ba8a4bf507>:0)
UnityEditor.Presets.PresetEditor.DrawPresetData () (at <5951c2421c324f47883bd5ba8a4bf507>:0)
UnityEditor.Presets.PresetEditor.OnInspectorGUI () (at <5951c2421c324f47883bd5ba8a4bf507>:0)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass58_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <5951c2421c324f47883bd5ba8a4bf507>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)