[python] Matplotlib: flush the plot store when the controller is popped

python/port/mod/matplotlib/plot_controller.cpp

@@ -0,0 +1,10 @@
+#include "plot_controller.h"
+
+namespace Matplotlib {
+
+void PlotController::viewDidDisappear() {
+  MicroPython::ExecutionViewControllerHelper::viewDidDisappear(this);
+  m_store->flush();
+}
+
+}