Call plugin teardown method when plugin is destroyed

Summary: `teardown()` was not called for device plugins. This diff fixes the issue.

Reviewed By: jknoxville

Differential Revision: D16416440

fbshipit-source-id: 5c9ffa211bfbe4e322504c37b95ff87afab8d061

src/PluginContainer.js

@@ -79,6 +79,13 @@ class PluginContainer extends PureComponent<Props> {
     }
   };
 
+  componentWillUnmount() {
+    if (this.plugin) {
+      this.plugin._teardown();
+      this.plugin = null;
+    }
+  }
+
   render() {
     const {
       pluginState,

src/plugin.js

@@ -164,6 +164,10 @@ export class FlipperDevicePlugin<S = *, A = *, P = *> extends FlipperBasePlugin<
     this.init();
   }
 
+  _teardown() {
+    this.teardown();
+  }
+
   static supportsDevice(device: BaseDevice) {
     throw new Error(
       'supportsDevice is unimplemented in FlipperDevicePlugin class',