[Android][Signin] Remove method isMobileIdentityConsistencyEnabled

This CL removes the unused method isMobileIdentityConsistencyEnabled.

Bug: 1035950
Change-Id: I39ce79e68a5e03ff281358673451a9bf4d8507c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1980740Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727482}

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninManager.java

@@ -298,8 +298,7 @@ public class SigninManager
      *         Google Play Services installed.
      */
     public boolean isSigninSupported() {
-        return !ApiCompatibilityUtils.isDemoUser() && isGooglePlayServicesPresent()
-                && !SigninManagerJni.get().isMobileIdentityConsistencyEnabled();
+        return !ApiCompatibilityUtils.isDemoUser() && isGooglePlayServicesPresent();
     }
 
     /**
@@ -715,8 +714,6 @@ public class SigninManager
 
         String extractDomainName(String email);
 
-        boolean isMobileIdentityConsistencyEnabled();
-
         void fetchAndApplyCloudPolicy(
                 long nativeSigninManagerAndroid, CoreAccountInfo account, Runnable callback);
 

chrome/browser/android/signin/signin_manager_android.cc

@@ -308,7 +308,3 @@ base::android::ScopedJavaLocalRef<jstring> JNI_SigninManager_ExtractDomainName(
   std::string domain = gaia::ExtractDomainName(email);
   return base::android::ConvertUTF8ToJavaString(env, domain);
 }
-
-jboolean JNI_SigninManager_IsMobileIdentityConsistencyEnabled(JNIEnv* env) {
-  return base::FeatureList::IsEnabled(signin::kMiceFeature);
-}