Fix importing lit under rollup v3

The updated https://www.npmjs.com/package/@rollup/plugin-node-resolve
plugin now looks inside package.json and uses that as a reference.
It looks at the exports field.

See I31f91e807b78d435631f5a0bdd358e5c75b04f3e
and I9f400ebb021e64dffe8828be04844e840c71f0ec.

Change-Id: I06527b5a2e705f9f4e1097aa00e642939516a5c5
diff --git a/web/rv-edit-screen.ts b/web/rv-edit-screen.ts
index e8f32a1..6c4729a 100644
--- a/web/rv-edit-screen.ts
+++ b/web/rv-edit-screen.ts
@@ -18,7 +18,7 @@
 import {RestPluginApi} from '@gerritcodereview/typescript-api/rest';
 import '@gerritcodereview/typescript-api/gerrit';
 import {css, CSSResult, html, LitElement} from 'lit';
-import {customElement, property, state} from 'lit/decorators';
+import {customElement, property, state} from 'lit/decorators.js';
 import './rv-filter-section';
 import {Section} from './rv-filter-section';
 import {fire} from './util';
diff --git a/web/rv-filter-section.ts b/web/rv-filter-section.ts
index c903f5e..15385ee 100644
--- a/web/rv-filter-section.ts
+++ b/web/rv-filter-section.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 import {css, CSSResult, html, LitElement, nothing} from 'lit';
-import {customElement, property, query, state} from 'lit/decorators';
+import {customElement, property, query, state} from 'lit/decorators.js';
 import {RestPluginApi} from '@gerritcodereview/typescript-api/rest';
 import {RepoName} from '@gerritcodereview/typescript-api/rest-api';
 import '@gerritcodereview/typescript-api/gerrit';
diff --git a/web/rv-reviewer.ts b/web/rv-reviewer.ts
index 4f5b7b9..f1eedad 100644
--- a/web/rv-reviewer.ts
+++ b/web/rv-reviewer.ts
@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {customElement, property, state} from 'lit/decorators';
+import {customElement, property, state} from 'lit/decorators.js';
 import {css, CSSResult, html, LitElement} from 'lit';
 import {RestPluginApi} from '@gerritcodereview/typescript-api/rest';
 import '@gerritcodereview/typescript-api/gerrit';
diff --git a/web/rv-reviewers.ts b/web/rv-reviewers.ts
index 847812d..306b3f2 100644
--- a/web/rv-reviewers.ts
+++ b/web/rv-reviewers.ts
@@ -18,7 +18,7 @@
 import {RestPluginApi} from '@gerritcodereview/typescript-api/rest';
 import {PluginApi} from '@gerritcodereview/typescript-api/plugin';
 import '@gerritcodereview/typescript-api/gerrit';
-import {customElement, property, query, state} from 'lit/decorators';
+import {customElement, property, query, state} from 'lit/decorators.js';
 import {css, CSSResult, html, LitElement} from 'lit';
 import './rv-edit-screen';