Component used: Fragment
Version used: 1.1.0-rc01 (part of AppCompat 1.1.0-rc01)
Devices/Android versions reproduced on: API 28 x86 emulator and Pixel 1

When using the new `BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT` behavior on a `FragmentStatePagerAdapter`, along with `getItemPosition()` returning `POSITION_NONE`, the app crashes when calling `notifyDataSetChanged()` on the adapter. We are using this paradigm to replace all of the fragments in the adapter.

Here's what seems to be happening. All of the fragments are removed in a fragment transaction (`ViewPager` calls `FragmentStatePagerAdapter#finishUpdate()` once the fragments are removed). Then the new fragments are instantiated and added to a new fragment transaction. The `ViewPager` then calls `setPrimaryItem` which tries to set the max lifecycle on the `mCurrentPrimaryItem`. However, this `mCurrentPrimaryItem` is still referencing the old fragment that was removed in a separate transaction, which causes the crash. It seems like the `mCurrentPrimaryItem` should be nulled out if it is removed from the adapter.

I've attached a sample project and GIF. To reproduce, just launch the app and press the `Replace Fragments` action button. Here's the error stacktrace:

2019-07-10 20:03:16.876 32176-32176/com.example.android.horizontalpaging E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.android.horizontalpaging, PID: 32176
java.lang.IllegalArgumentException: Cannot setMaxLifecycle for Fragment not attached to FragmentManager FragmentManager{9187988 in HostCallbacks{ba35f21}}
at androidx.fragment.app.BackStackRecord.setMaxLifecycle(BackStackRecord.java:244)
at androidx.fragment.app.FragmentStatePagerAdapter.setPrimaryItem(FragmentStatePagerAdapter.java:234)
at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1234)
at androidx.viewpager.widget.ViewPager.setCurrentItemInternal(ViewPager.java:669)
at androidx.viewpager.widget.ViewPager.setCurrentItemInternal(ViewPager.java:631)
at androidx.viewpager.widget.ViewPager.dataSetChanged(ViewPager.java:1086)
at androidx.viewpager.widget.ViewPager$PagerObserver.onChanged(ViewPager.java:3097)
at androidx.viewpager.widget.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:291)
at com.example.android.horizontalpaging.MainActivity.onOptionsItemSelected(MainActivity.java:67)
at android.app.Activity.onMenuItemSelected(Activity.java:3544)
at androidx.fragment.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:384)
at com.android.internal.policy.PhoneWindow.onMenuItemSelected(PhoneWindow.java:1237)
at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:776)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:148)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:923)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:913)
at android.widget.ActionMenuView.invokeItem(ActionMenuView.java:617)
at com.android.internal.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:147)
at android.view.View.performClick(View.java:6597)
at android.view.View.performClickInternal(View.java:6574)
at android.view.View.access$3100(View.java:778)
at android.view.View$PerformClick.run(View.java:25885)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6718)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)