test: Fix flaky player integration test (#3936)
test: Fix flaky player integration test (#3936)

Instead of waiting for the playhead to reach a specific time that we
know to be the end, then expecting ended to be true, we can use the
purpose-built waiter that waits for the ended event.

We also need to set the timeout explicitly, so that we have enough
time to play through to the end.
shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player