使用ConcatAdapter时，设置的itemType无效报错

使用ConcatAdapter包裹两个这个adapter时，在显示时，拿到的itemType并不是设置的值，导致找不到provider，报空指针错误
Process: com.donkingliang.consecutivescroller, PID: 13316
kotlin.KotlinNullPointerException
at com.chad.library.adapter.base.BaseProviderMultiAdapter.convert(BaseProviderMultiAdapter.kt:57)
at com.chad.library.adapter.base.BaseQuickAdapter.onBindViewHolder(BaseQuickAdapter.kt:376)
at com.chad.library.adapter.base.BaseQuickAdapter.onBindViewHolder(BaseQuickAdapter.kt:382)
at com.chad.library.adapter.base.BaseQuickAdapter.onBindViewHolder(BaseQuickAdapter.kt:75)
at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:7258)
at androidx.recyclerview.widget.NestedAdapterWrapper.onBindViewHolder(NestedAdapterWrapper.java:157)
at androidx.recyclerview.widget.ConcatAdapterController.onBindViewHolder(ConcatAdapterController.java:368)
at androidx.recyclerview.widget.ConcatAdapter.onBindViewHolder(ConcatAdapter.java:188)

Start by reproducing the issue with two adapters wrapped in AndroidX ConcatAdapter, then inspect BaseProviderMultiAdapter.convert and the BaseQuickAdapter.onBindViewHolder paths named in the stack trace. Done means the configured itemType is preserved during binding, the correct provider is found, and the null-pointer failure no longer occurs.