fix: formAssociated being stripped from closure

PiperOrigin-RevId: 534091935

Author: asyncliz

checkbox/lib/checkbox.ts

@@ -27,7 +27,9 @@ export class Checkbox extends LitElement {
   }
 
   /** @nocollapse */
-  static formAssociated = true;
+  static get formAssociated() {
+    return true;
+  }
 
   /**
    * Whether or not the checkbox is selected.

radio/lib/radio.ts

@@ -33,7 +33,9 @@ export class Radio extends LitElement {
       ShadowRootInit = {...LitElement.shadowRootOptions, delegatesFocus: true};
 
   /** @nocollapse */
-  static formAssociated = true;
+  static get formAssociated() {
+    return true;
+  }
 
   /**
    * Whether or not the radio is selected.

slider/lib/slider.ts

@@ -61,10 +61,10 @@ export class Slider extends LitElement {
   static override shadowRootOptions:
       ShadowRootInit = {...LitElement.shadowRootOptions, delegatesFocus: true};
 
-  /**
-   * @nocollapse
-   */
-  static formAssociated = true;
+  /** @nocollapse */
+  static get formAssociated() {
+    return true;
+  }
 
   /**
    * Whether or not the slider is disabled.

switch/lib/switch.ts

@@ -31,10 +31,10 @@ export class Switch extends LitElement {
   static override shadowRootOptions:
       ShadowRootInit = {mode: 'open', delegatesFocus: true};
 
-  /**
-   * @nocollapse
-   */
-  static formAssociated = true;
+  /** @nocollapse */
+  static get formAssociated() {
+    return true;
+  }
 
   /**
    * Disables the switch and makes it non-interactive.