Cleanup of some of the unused code from DRP params

(i) Secure proxy holdback field trial is not being
used anymore. Effectively,
IsIncludedInSecureProxyHoldbackFieldTrial() now always returns
false.

(ii) Enabling/disabling quic for non-core data saver
proxies is not used anymore. Effectively,
IsQuicEnabledForNonCoreProxies() now always returns
true.

Change-Id: I356e0d9fc8409d9458119462fac33a43a8550e56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1584780
Reviewed-by: Robert Ogden <robertogden@chromium.org>
Reviewed-by: rajendrant <rajendrant@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654140}
6 files changed