Launch SecurityHub fragment on SECURITY_SETTINGS intent when available.

Test: atest SettingsUnitTests
Test: adb shell am start -a android.settings.SECURITY_SETTINGS opens
SecurityHub screen (when SecurityHub enabled)
Test: assistant opens SecurityHub screen (when SecurityHub enabled) when
given instrucion to "open security settings"
Bug: 183930061

Change-Id: Ie8fcb2f2dce4cd0a2a84c6cd21a0a1c0b2b3665e
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index c89402c..d28f86d 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -19,11 +19,14 @@
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
+import android.text.TextUtils;
 import android.util.FeatureFlagUtils;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.settings.core.FeatureFlags;
 import com.android.settings.enterprise.EnterprisePrivacySettings;
 import com.android.settings.overlay.FeatureFactory;
+import com.android.settings.security.SecuritySettingsFeatureProvider;
 
 /**
  * Top-level Settings activity
@@ -118,7 +121,39 @@
      * Activity for Reduce Bright Colors.
      */
     public static class ReduceBrightColorsSettingsActivity extends SettingsActivity { /* empty */ }
-    public static class SecurityDashboardActivity extends SettingsActivity { /* empty */ }
+    /** Activity for the security dashboard. */
+    public static class SecurityDashboardActivity extends SettingsActivity {
+
+        /** Whether the given fragment is allowed. */
+        @VisibleForTesting
+        @Override
+        public boolean isValidFragment(String fragmentName) {
+            return super.isValidFragment(fragmentName)
+                    || (fragmentName != null
+                            && TextUtils.equals(fragmentName, getAlternativeFragmentName()));
+        }
+
+        @Override
+        public String getInitialFragmentName(Intent intent) {
+            final String alternativeFragmentName = getAlternativeFragmentName();
+            if (alternativeFragmentName != null) {
+                return alternativeFragmentName;
+            }
+
+            return super.getInitialFragmentName(intent);
+        }
+
+        private String getAlternativeFragmentName() {
+            String alternativeFragmentClassname = null;
+            final SecuritySettingsFeatureProvider securitySettingsFeatureProvider =
+                    FeatureFactory.getFactory(this).getSecuritySettingsFeatureProvider();
+            if (securitySettingsFeatureProvider.hasAlternativeSecuritySettingsFragment()) {
+                alternativeFragmentClassname = securitySettingsFeatureProvider
+                        .getAlternativeSecuritySettingsFragmentClassname();
+            }
+            return alternativeFragmentClassname;
+        }
+    }
     public static class UsageAccessSettingsActivity extends SettingsActivity { /* empty */ }
     public static class AppUsageAccessSettingsActivity extends SettingsActivity { /* empty */ }
     public static class LocationSettingsActivity extends SettingsActivity { /* empty */ }