Android: Fix rendering of settings background in dark mode

This amends faad83d5a3 by undoing the
insertion of a QScrollArea + QWidget under the whole form. The reason
for adding this was to be able to scroll down to the license agreements.

Since Core::SettingsDialog already puts the settings widget into a
QScrollArea, we have two of those and one is superfluous. When using a
dark theme (e.g. flat-dark), this extra QScrollArea introduces wrong
background color. Also, it complicates the already quite blown
androidsettingswidget.ui

This change removes the QSrollArea + QWidget while keeping the feature
of scrolling to the license text. This is achieved by searching through
the parent chain for a QScrollArea and using the first found one for
scrolling.

Task-number: QTCREATORBUG-24379
Change-Id: I2bdae9367eb06b68fa47badf2556eb1ec7ebcafb
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

src/plugins/android/androidsettingswidget.cpp

@@ -56,6 +56,7 @@
 #include <QLoggingCategory>
 #include <QMessageBox>
 #include <QModelIndex>
+#include <QScrollArea>
 #include <QSettings>
 #include <QString>
 #include <QTimer>
@@ -367,7 +368,14 @@ AndroidSettingsWidget::AndroidSettingsWidget()
         m_ui.managerTabWidget->tabBar()->setEnabled(true);
     });
     connect(m_sdkManagerWidget, &AndroidSdkManagerWidget::licenseWorkflowStarted, [this] {
-       m_ui.scrollArea->ensureWidgetVisible(m_ui.managerTabWidget);
+        QObject *parentWidget = parent();
+        while (parentWidget) {
+            if (auto scrollArea = qobject_cast<QScrollArea *>(parentWidget)) {
+                scrollArea->ensureWidgetVisible(m_ui.managerTabWidget);
+                break;
+            }
+            parentWidget = parentWidget->parent();
+        };
     });
 
     QMap<int, QString> javaValidationPoints;