[REG 6.8.3->6.9] Android QtNative.updateNativeActivity() Fails At Startup: Safe Area Transgressions

Android apps reliably fail to initialise the QtActivity, with a JNI call not found, leading to safe area transgressions and probably other faults. The error message

: No implementation found for boolean org.qtproject.qt.android.QtNative.updateNativeActivity() (tried Java_org_qtproject_qt_android_QtNative_updateNativeActivity and Java_org_qtproject_qt_android_QtNative_updateNativeActivity__) - is the library loaded, e.g. System.loadLibrary?

 is emitted early in the startup sequence (before "I/QtCore : Start")

The immediate consequence is that the app displays outside the safe area: see the screenshot.

The QML application used is a default one created with QtCreator 16.0.2 with the QML:

import QtQuick
Window {
    width: 640
    height: 480
    visible: true
    Rectangle {
        anchors.fill: parent
        color: "#333333"
    }
    TextEdit {
        color: "#ffffff"
        anchors.fill: parent
    }
    title: qsTr("Safe Area Test")
}
 

A simple QWidgets app has the same problem, and the effects are more pronounced, with very large errors in the layout contents margins when a QTextEdit is used.