Android: Reset m_usePrimaryClip when clearing the clip data

The variable needs to be set to false when we clear the clip data as
there is no primary clip anymore so we should not try to access it when
setting new data.

Fixes: QTBUG-93831
Change-Id: I309270dc075fcb0457607561ee23e12f7eb6397f
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
(cherry picked from commit 96982bab0c5ff855100c1dcde23d090348be53db)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/android/jar/src/org/qtproject/qt/android/QtNative.java

@@ -1006,6 +1006,7 @@ public class QtNative
     {
         if (Build.VERSION.SDK_INT >= 28 && m_clipboardManager != null)
             m_clipboardManager.clearPrimaryClip();
+         m_usePrimaryClip = false;
     }
     private static void setClipboardText(String text)
     {