feat(qr-scanner): added destroy method (#1916) (#1971)

fix(qr-scanner): added destroy method (#1916)

Author: Inconspicuously

src/@ionic-native/plugins/qr-scanner/index.ts

@@ -159,6 +159,13 @@ export class QRScanner extends IonicNativePlugin {
   })
   enableLight(): Promise<QRScannerStatus> { return; }
 
+  /**
+   * Destroy the scanner instance.
+   * @returns {Promise<QRScannerStatus>}
+   */
+  @Cordova()
+  destroy(): Promise<QRScannerStatus> { return; }
+
   /**
    * Disable the device's light.
    * @return {Promise<QRScannerStatus>}