Test Watch App's battery usage when streaming

[mchowning]

Battery usage is a big concern on watches, so let's do some testing of the watch app and see how it's battery performance is when it is streaming podcasts compared to when it is playing downloaded podcasts.

[mchowning]

Tested streaming performance when on wifi, and it showed no difference. I had the same battery usage on my device both when streaming a particular episode over wifi and when playing that same episode after downloading it.

Still need to test this when on LTE though.

[mchowning]

I compared streaming through wifi with streaming through LTE and noticed no significant difference (LTE actually used less battery in my test).