Update import statements

Author: hsubox76

packages-exp/messaging-exp/rollup.config.js

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import json from 'rollup-plugin-json';
+import json from '@rollup/plugin-json';
 import pkg from './package.json';
 import typescript from 'typescript';
 import typescriptPlugin from 'rollup-plugin-typescript2';

packages-exp/messaging-exp/rollup.config.release.js

@@ -16,7 +16,7 @@
  */
 
 import { importPathTransformer } from '../../scripts/exp/ts-transform-import-path';
-import json from 'rollup-plugin-json';
+import json from '@rollup/plugin-json';
 import pkg from './package.json';
 import typescript from 'typescript';
 import typescriptPlugin from 'rollup-plugin-typescript2';