Switch Android ContextMenu Implementation

[mpiannucci]

This PR switches to use the native Android ContextMenu

Changes:

• ContextMenu will now show where the user clicks, consistent with android native functionality
• Nested Items are now supported on Android, the same as iOS

Breaking:

• This may break icon functionality on android because I don't believe android ContextMenu's can have icons. @VidocqH can you test or chime in here before i merge this?

[VidocqH]

Since ContextMenu inherits from Menu, it should be created by MenuBuilder, so we can always use reflection to let it displays icons.

Parent Menu:

Child Menu(as a poc, I only set one icon here):

    private void setMenuIconDisplay(Menu contextMenu, boolean display) {
        try {
            Class<?> clazz = Class.forName("com.android.internal.view.menu.MenuBuilder");
            Method m = clazz.getDeclaredMethod("setOptionalIconsVisible", boolean.class);
            m.setAccessible(true);
            m.invoke(contextMenu, display);
        } catch (Exception ignored) {}
    }

    // Submenu example
    private void createContextMenuSubMenu(Menu menu, ReadableMap action, ReadableArray childActions, int i) {
        String title = action.getString("title");
        Menu parentMenu = menu.addSubMenu(title);

        @Nullable Drawable systemIcon = getResourceWithName(getContext(), action.getString("systemIcon"));
        menu.getItem(i).setIcon(systemIcon);  // set icon to current item.

        for (int j = 0; j < childActions.size(); j++) {
            createContextMenuAction(parentMenu, childActions.getMap(j), j, i);
        }
    }

    @Override
    public void onCreateContextMenu(ContextMenu contextMenu, View view, ContextMenu.ContextMenuInfo contextMenuInfo) {
        contextMenu.clear();
        setMenuIconDisplay(contextMenu, true);
        ...
    }

[mpiannucci]

Thanks! That worked perfectly!