Revert "Enable IntentBlockExternalFormRedirectsNoGesture by default"

This reverts commit d67cf55d.

Reason for revert: Still breaks some SSO flows

Original change's description:
> Enable IntentBlockExternalFormRedirectsNoGesture by default
> 
> Bug: 927509
> Change-Id: I56ec8b5cf524a4e1d14b29427931802f80d54a3f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2132197
> Reviewed-by: Ted Choc <tedchoc@chromium.org>
> Commit-Queue: Jochen Eisinger <jochen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#771584}

TBR=tedchoc@chromium.org,jochen@chromium.org

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

Bug: 927509
Change-Id: I2fb4e6b38de9224cbf1f3be8dd3fd241bb860b11
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2225898Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774070}

components/external_intents/android/external_intents_feature_list.cc

@@ -36,7 +36,7 @@ const base::Feature* FindFeatureExposedToJava(const std::string& feature_name) {
 // Alphabetical:
 const base::Feature kIntentBlockExternalFormRedirectsNoGesture{
     "IntentBlockExternalFormRedirectsNoGesture",
-    base::FEATURE_ENABLED_BY_DEFAULT};
+    base::FEATURE_DISABLED_BY_DEFAULT};
 
 static jboolean JNI_ExternalIntentsFeatureList_IsEnabled(
     JNIEnv* env,