-Retrieving array element that was out of bounds error is thrown on deleting Missing Camera element from Camera.
-UnassignedReferenceException exceptions are thrown continuously on removing missing camera element from the stack list of camera prefab.
-Overlay Camera is missing in stack list of the base camera prefab.

Steps to repro:
1. Create a new project with the URP template > Create New Scene.
2. GameObject > Camera > Change Render Type to Overlay.
3. Main Camera > Stack > Add Overlay camera.
4. Create prefab of the Main Camera.

Actual Result:
-Overlay Camera should be available in Stack list of Main Camera prefab.
-UnassignedReferenceException and Retrieving array element that was out of bounds exceptions are thrown in the console.

Expected Result:
No error in the console.

Reproducible in:
2020.2.0a9, 2020.1.0b8, 2019.3.0f6 with Package Version: 9.0.0, 8.0.1, 7.3.1, 7.2.1, 7.2.0.

Note: Overlay Render type is introduced in Package Version: 7.2.0

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
Retrieving array element that was out of bounds
UnityEditor.SerializedProperty:DeleteArrayElementAtIndex(Int32)
UnityEditorInternal.Defaults:DoRemoveButton(ReorderableList)
UnityEditor.Rendering.Universal.UniversalRenderPipelineCameraEditor:<UpdateCameras>b__45_0(ReorderableList)
UnityEditorInternal.Defaults:DrawFooter(Rect, ReorderableList)
UnityEditorInternal.ReorderableList:DoListFooter(Rect)
UnityEditorInternal.ReorderableList:DoLayoutList()
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

UnassignedReferenceException: The variable m_Cameras of UniversalAdditionalCameraData has not been assigned.
You probably need to assign the m_Cameras variable of the UniversalAdditionalCameraData script in the inspector.
UnityEngine.Rendering.Universal.UniversalRenderPipeline.RenderCameraStack (UnityEngine.Rendering.ScriptableRenderContext context, UnityEngine.Camera baseCamera) (at library/packagecache/com.unity.render-pipelines.universal@9.0.0-preview.14/runtime/universalrenderpipeline.cs:326)
UnityEngine.Rendering.Universal.UniversalRenderPipeline.Render (UnityEngine.Rendering.ScriptableRenderContext renderContext, UnityEngine.Camera[] cameras) (at library/packagecache/com.unity.render-pipelines.universal@9.0.0-preview.14/runtime/universalrenderpipeline.cs:148)
UnityEngine.Rendering.RenderPipeline.InternalRender (UnityEngine.Rendering.ScriptableRenderContext context, UnityEngine.Camera[] cameras) (at <2ab2854ade474944aaaee820c644f328>:0)
UnityEngine.Rendering.RenderPipelineManager.DoRenderLoop_Internal (UnityEngine.Rendering.RenderPipelineAsset pipe, System.IntPtr loopPtr, Unity.Collections.LowLevel.Unsafe.AtomicSafetyHandle safety) (at <2ab2854ade474944aaaee820c644f328>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)