docs(density): mark extra api as internal as intended (#14381)

Author: damyanpetev

projects/igniteui-angular/src/lib/core/density.ts

@@ -193,6 +193,7 @@ export class DisplayDensityBase implements DoCheck, OnInit {
 
     /**
      * Sets the `--component-size` CSS variable based on the value of Display Density
+     * @hidden @internal
      */
     public getComponentSizeStyles() {
         switch (this._displayDensity || this.oldDisplayDensityOptions.displayDensity) {