[Android] Honor Brave Rewards disabled-by-policy pref (#35651)

brave_rewards::IsDisabledByPolicy() was hardcoded to return false on
Android regardless of the managed kDisabledByPolicy pref, so every
native call site that gates on brave_rewards::IsSupported() failed to
suppress for Brave Origin subscribers (and enterprise admins setting
the BraveRewardsDisabled policy).

Symptoms fixed:
- Ads service kept initializing on Android for Origin profiles
  (AdsServiceFactory::GetForProfile gates on IsSupported).
- NTP sponsored background images and sponsored rich-media takeover
  rendered (downstream of the ads service via ViewCounterService).
- DAY_10 / DAY_30 / DAY_35 Rewards retention notifications fired
  (RetentionNotificationPublisher gates on rewardsNativeWorker
  .isSupported).

Java-side Rewards UI surfaces were already correctly gated via
BraveRewardsPolicy.isDisabledByPolicy(profile) and are unaffected.

Also decouples BraveVpnUtils.isRegionSupported() from
BraveRewardsNativeWorker.isSupported() — otherwise the guard flip would
cause VPN UI to hide for any profile where Rewards is policy-disabled
as a side effect. Added BraveVpnNativeWorker.isSupportedRegion that
does the OFAC region check directly via brave_l10n.

Resolves: https://github.com/brave/brave-browser/issues/54703

android/java/org/chromium/chrome/browser/vpn/BraveVpnNativeWorker.java

@@ -176,6 +176,10 @@ public class BraveVpnNativeWorker {
         return BraveVpnNativeWorkerJni.get().isPurchasedUser(mNativeBraveVpnNativeWorker);
     }
 
+    public boolean isSupportedRegion() {
+        return BraveVpnNativeWorkerJni.get().isSupportedRegion(mNativeBraveVpnNativeWorker);
+    }
+
     public void getSubscriberCredentialV12() {
         BraveVpnNativeWorkerJni.get().getSubscriberCredentialV12(mNativeBraveVpnNativeWorker);
     }
@@ -239,6 +243,8 @@ public class BraveVpnNativeWorker {
 
         boolean isPurchasedUser(long nativeBraveVpnNativeWorker);
 
+        boolean isSupportedRegion(long nativeBraveVpnNativeWorker);
+
         void getSubscriberCredentialV12(long nativeBraveVpnNativeWorker);
 
         void reportBackgroundP3A(

android/java/org/chromium/chrome/browser/vpn/utils/BraveVpnUtils.java

@@ -26,7 +26,6 @@ import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.brave_vpn.mojom.BraveVpnConstants;
 import org.chromium.brave_vpn.mojom.Region;
-import org.chromium.chrome.browser.BraveRewardsNativeWorker;
 import org.chromium.chrome.browser.vpn.BraveVpnNativeWorker;
 import org.chromium.chrome.browser.vpn.activities.BraveVpnProfileActivity;
 import org.chromium.chrome.browser.vpn.activities.BraveVpnSupportActivity;
@@ -310,8 +309,8 @@ public class BraveVpnUtils {
     }
 
     private static boolean isRegionSupported() {
-        BraveRewardsNativeWorker braveRewardsNativeWorker = BraveRewardsNativeWorker.getInstance();
-        return (braveRewardsNativeWorker != null && braveRewardsNativeWorker.isSupported());
+        BraveVpnNativeWorker braveVpnNativeWorker = BraveVpnNativeWorker.getInstance();
+        return braveVpnNativeWorker != null && braveVpnNativeWorker.isSupportedRegion();
     }
 
     public static boolean isVpnFeatureSupported(Context context) {

browser/DEPS

@@ -129,6 +129,10 @@ specific_include_rules = {
   "brave_local_state_prefs\.cc": [
     "!brave/components/l10n/common/prefs.h",
   ],
+  "brave_vpn_native_worker\.cc": [
+    "!brave/components/l10n/common/locale_util.h",
+    "!brave/components/l10n/common/ofac_sanction_util.h",
+  ],
   "brave_browser_process_impl\.cc": [
     "+brave/components/brave_component_updater/browser/brave_component_updater_delegate.h",
     "+brave/components/brave_component_updater/browser/local_data_files_service.h",

browser/brave_vpn/android/brave_vpn_native_worker.cc

@@ -13,6 +13,8 @@
 #include "base/values.h"
 #include "brave/browser/brave_vpn/brave_vpn_service_factory.h"
 #include "brave/components/brave_vpn/browser/brave_vpn_service.h"
+#include "brave/components/l10n/common/locale_util.h"
+#include "brave/components/l10n/common/ofac_sanction_util.h"
 #include "chrome/android/chrome_jni_headers/BraveVpnNativeWorker_jni.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
@@ -260,6 +262,11 @@ void BraveVpnNativeWorker::ReloadPurchasedState(JNIEnv* env) {
   }
 }
 
+bool BraveVpnNativeWorker::IsSupportedRegion(JNIEnv* env) {
+  return !brave_l10n::IsISOCountryCodeOFACSanctioned(
+      brave_l10n::GetDefaultISOCountryCodeString());
+}
+
 void BraveVpnNativeWorker::ReportForegroundP3A(JNIEnv* env) {
   BraveVpnService* brave_vpn_service = GetBraveVpnService();
   if (brave_vpn_service) {

browser/brave_vpn/android/brave_vpn_native_worker.h

@@ -94,6 +94,8 @@ class BraveVpnNativeWorker {
 
   jboolean IsPurchasedUser(JNIEnv* env);
 
+  bool IsSupportedRegion(JNIEnv* env);
+
   void ReportForegroundP3A(JNIEnv* env);
   void ReportBackgroundP3A(JNIEnv* env,
                            jlong session_start_time_ms,

browser/brave_vpn/sources.gni

@@ -57,6 +57,7 @@ if (enable_brave_vpn) {
     ]
     brave_browser_brave_vpn_deps += [
       "//brave/build/android:jni_headers",
+      "//brave/components/l10n/common",
       "//mojo/public/cpp/bindings",
     ]
   }

components/brave_rewards/core/rewards_util.cc

@@ -9,6 +9,7 @@
 
 #include "base/check.h"
 #include "base/no_destructor.h"
+#include "brave/components/brave_rewards/core/pref_names.h"
 #include "brave/components/l10n/common/locale_util.h"
 #include "brave/components/l10n/common/ofac_sanction_util.h"
 #include "build/build_config.h"
@@ -19,22 +20,14 @@
 #include "brave/components/brave_rewards/core/features.h"
 #endif  // BUILDFLAG(IS_ANDROID)
 
-#if !BUILDFLAG(IS_ANDROID)
-#include "brave/components/brave_rewards/core/pref_names.h"
-#endif  // !BUILDFLAG(IS_ANDROID)
-
 namespace brave_rewards {
 
 namespace {
 
 bool IsDisabledByPolicy(PrefService* prefs) {
-#if BUILDFLAG(IS_ANDROID)
-  return false;
-#else
   DCHECK(prefs);
   return prefs->IsManagedPreference(prefs::kDisabledByPolicy) &&
          prefs->GetBoolean(prefs::kDisabledByPolicy);
-#endif
 }
 
 bool IsDisabledByFeature() {