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}

services/network/public/cpp/features.cc

@@ -177,11 +177,7 @@ const char kCorbAllowlistAlsoAppliesToOorCorsParamName[] =
 // 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