Add cipd dependencies to try/ci builders

Added following dependencies:
- android ndk
- mips-img-linux-gnu
- mips-mti-linux-gnu

Also, prevent InfraFailures on cipd.ensure when $codecs/prerequisites is empty.

Change-Id: I88bf4498b3990ded4a65d62c35aaf709eb996fc7
Bug: b:185520507
Reviewed-on: https://chromium-review.googlesource.com/c/codecs/infra/+/3224013
Commit-Queue: Roberto Alanis Baez <alanisbaez@google.com>
Reviewed-by: James Zern <jzern@google.com>