Reland "Enable |request_initiator_site_lock| enforcement on Android."

This reverts commit 207fb0e1.

Reason for revert: Trying again on M89 (with new crash keys from https://crrev.com/c/2575368)

Original change's description:
> Revert "Enable |request_initiator_site_lock| enforcement on Android."
>
> This reverts commit becee7ed.
>
> Reason for revert: Spike on M88 - most likely caused by https://crbug.com/1151008 and https://crbug.com/1151438
>
> Original change's description:
> > Enable |request_initiator_site_lock| enforcement on Android.
> >
> > The "RequestInitiatorSiteLockEnfocement" feature is enabled on desktop
> > platforms in M87, because we want to be more careful on Android, since a
> > mojo::ReportBadMessage might lead there to renderer kills (if
> > NetworkService is hosted in the Browser process, something that never
> > happens on desktop platforms).
> >
> > Since the M87 data so far looks good so far [1], this CL enables the
> > enforcement on all platforms for M88.
> >
> > [1] https://docs.google.com/document/d/132ZPqDZdH-rcvBvHEAd-m86P2udVCi07ccnI0DXmJgE/edit#
> >
> > Bug: 920634
> > Change-Id: I5f27d9402b3e60668305312aa437252554890bc8
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2465803
> > Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
> > Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
> > Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#816410}
>
> TBR=yhirano@chromium.org,lukasza@chromium.org
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Bug: 920634, 1151008, 1151438
> Change-Id: I7b2157914d8a091d21ce55bfc108c3029a4ff4aa
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2575358
> Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
> Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#833868}

TBR=yhirano@chromium.org,lukasza@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 920634
Bug: 1151008
Bug: 1151438
Change-Id: Iff849597312d7843b1fff809a00743d0785680e8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2578100Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834521}

services/network/public/cpp/features.cc

@@ -155,11 +155,7 @@ const base::Feature kDisableKeepaliveFetch{"DisableKeepaliveFetch",
 // See also https://crbug.com/920634
 const base::Feature kRequestInitiatorSiteLockEnfocement = {
     "RequestInitiatorSiteLockEnfocement",
-#if defined(OS_ANDROID)
-    base::FEATURE_DISABLED_BY_DEFAULT};
-#else
     base::FEATURE_ENABLED_BY_DEFAULT};
-#endif
 
 // When the CertVerifierService is enabled, certificate verification will not be
 // performed in the network service, but will instead be brokered to a separate