fix: wait till play event to listen for user activity (#5093)

There is no need to listen for user activity until a play is requested on the player and it just adds an extra timer for a player that hasn't started playing yet. Instead, just wait till the first `play` event.

Closes #5076.

src/js/player.js

@@ -468,8 +468,8 @@ class Player extends Component {
     // like the control bar show themselves if needed
     this.userActive(true);
     this.reportUserActivity();
-    this.listenForUserActivity_();
 
+    this.one('play', this.listenForUserActivity_);
     this.on('fullscreenchange', this.handleFullscreenChange_);
     this.on('stageclick', this.handleStageClick_);
 

test/unit/player.test.js

@@ -914,6 +914,8 @@ QUnit.test('should honor default inactivity timeout', function(assert) {
   // default timeout is 2000ms
   const player = TestHelpers.makePlayer({});
 
+  player.trigger('play');
+
   assert.equal(player.userActive(), true, 'User is active on creation');
   clock.tick(1800);
   assert.equal(player.userActive(), true, 'User is still active');
@@ -932,6 +934,8 @@ QUnit.test('should honor configured inactivity timeout', function(assert) {
     inactivityTimeout: 200
   });
 
+  player.trigger('play');
+
   assert.equal(player.userActive(), true, 'User is active on creation');
   clock.tick(150);
   assert.equal(player.userActive(), true, 'User is still active');