fix(ui5-dialog): resize handle is no longer shown on phones (#4326)

Fixes: #4253

Author: dimovpetar

packages/main/src/Dialog.hbs

@@ -23,7 +23,7 @@
 			<slot name="footer"></slot>
 		</footer>
 	{{/if}}
-	{{#if resizable}}
+	{{#if _showResizeHandle }}
 		<ui5-icon
 			name="resize-corner"
 			dir="{{effectiveDir}}"

packages/main/src/Dialog.js

@@ -277,6 +277,10 @@ class Dialog extends Popup {
 		return this._movable ? "0" : undefined;
 	}
 
+	get _showResizeHandle() {
+		return this.resizable && this.onDesktop;
+	}
+
 	_show() {
 		super._show();
 		this._center();