Remove the feature flag for Seccomp-BPF on Android.

The feature experiment has launched to 100% and is no longer needed.

Bug: 166704
Change-Id: I6fab725e6789d623a881a5bed4d6b42216c0677c
Reviewed-on: https://chromium-review.googlesource.com/521927
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477048}
7 files changed