Make FlexContainer be default-accessed

DEVSIX-5169

Author: ars18wrw

layout/src/main/java/com/itextpdf/layout/element/FlexContainer.java

@@ -45,7 +45,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.layout.renderer.FlexContainerRenderer;
 import com.itextpdf.layout.renderer.IRenderer;
 
-public class FlexContainer extends Div {
+class FlexContainer extends Div {
 
     public FlexContainer() {
         super();

layout/src/test/java/com/itextpdf/layout/FlexContainerTest.java renamed to layout/src/test/java/com/itextpdf/layout/element/FlexContainerTest.java

@@ -20,14 +20,16 @@ This file is part of the iText (R) project.
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package com.itextpdf.layout;
+package com.itextpdf.layout.element;
 
 import com.itextpdf.io.LogMessageConstant;
 import com.itextpdf.io.image.ImageDataFactory;
 import com.itextpdf.kernel.colors.ColorConstants;
 import com.itextpdf.kernel.pdf.PdfDocument;
 import com.itextpdf.kernel.pdf.PdfWriter;
 import com.itextpdf.kernel.utils.CompareTool;
+import com.itextpdf.layout.Document;
+import com.itextpdf.layout.Style;
 import com.itextpdf.layout.borders.SolidBorder;
 import com.itextpdf.layout.element.AreaBreak;
 import com.itextpdf.layout.element.Div;