Fix compilation issues for android

Deals with:
  * unknown class name 'Object'; did you mean 'QObject'?
  * use of undeclared identifier 'QTimer'; did you mean 'QTime'?

Pick-to: 6.5
Change-Id: Id63064e70090ed1f816fa19db047b382220d634c
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

src/corelib/platform/android/qandroidnativeinterface.cpp

@@ -10,6 +10,7 @@
 #include <QtCore/qfuture.h>
 #include <QtCore/qfuturewatcher.h>
 #include <QtCore/qpromise.h>
+#include <QtCore/qtimer.h>
 #include <QtCore/qthreadpool.h>
 #include <deque>
 #include <memory>

src/plugins/platforms/android/androidcontentfileengine.cpp

@@ -11,6 +11,8 @@
 #include <QtCore/qdatetime.h>
 #include <QtCore/qmimedatabase.h>
 
+QT_BEGIN_NAMESPACE
+
 using namespace QNativeInterface;
 using namespace Qt::StringLiterals;
 
@@ -823,4 +825,6 @@ bool DocumentFile::rename(const QString &newName)
     return false;
 }
 
+QT_END_NAMESPACE
+
 // End of DocumentFile

src/plugins/platforms/android/androidcontentfileengine.h

@@ -9,6 +9,8 @@
 #include <QtCore/qjniobject.h>
 #include <QtCore/qlist.h>
 
+QT_BEGIN_NAMESPACE
+
 using DocumentFilePtr = std::shared_ptr<class DocumentFile>;
 
 class AndroidContentFileEngine : public QFSFileEngine
@@ -102,4 +104,6 @@ protected:
     DocumentFilePtr m_parent;
 };
 
+QT_END_NAMESPACE
+
 #endif // ANDROIDCONTENTFILEENGINE_H