Chromecast: Fix redundant field initializations

In preparation for enabling an ErrorProne check to ban them

Bug: 878853
Change-Id: I267c5260c03e768ebcb732fed1a8966c4f598857
Reviewed-on: https://chromium-review.googlesource.com/1214086
Reviewed-by: Simeon Anfinrud <sanfin@chromium.org>
Commit-Queue: Aiden Benner <abenner@google.com>
Cr-Commit-Position: refs/heads/master@{#589900}
8 files changed