Adding a new internal method to get all valid scorers.

New NetworkScoreManager method to get all valid scorers from the
NetworkScoreService. The implementation is stubbed out for the time
being.

Test: make
Bug: 35095406
Change-Id: Iece2cc10a0a9377f2d82385d172b06660bb9b130

core/java/android/net/INetworkScoreService.aidl

@@ -132,5 +132,14 @@ interface INetworkScoreService
     oneway void requestRecommendationAsync(in RecommendationRequest request,
                                            in RemoteCallback remoteCallback);
 
+    /**
+     * Returns metadata about the active scorer or <code>null</code> if there is no active scorer.
+     */
     NetworkScorerAppManager.NetworkScorerAppData getActiveScorer();
+
+    /**
+     * Returns the list of available scorer apps. The list will be empty if there are
+     * no valid scorers.
+     */
+    List<NetworkScorerAppManager.NetworkScorerAppData> getAllValidScorers();
 }

core/java/android/net/NetworkScoreManager.java

@@ -37,6 +37,7 @@ import com.android.internal.util.Preconditions;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
 /**
@@ -199,6 +200,20 @@ public class NetworkScoreManager {
         }
     }
 
+    /**
+     * Returns the list of available scorer apps. The list will be empty if there are
+     * no valid scorers.
+     *
+     * @hide
+     */
+    public List<NetworkScorerAppData> getAllValidScorers() {
+        try {
+            return mService.getAllValidScorers();
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
     /**
      * Update network scores.
      *

core/java/android/net/NetworkScorerAppManager.java

@@ -126,6 +126,14 @@ public class NetworkScorerAppManager {
         }
     }
 
+    /**
+     * Returns the list of available scorer apps. The list will be empty if there are
+     * no valid scorers.
+     */
+    public List<NetworkScorerAppData> getAllValidScorers() {
+        return Collections.emptyList();
+    }
+
     /**
      * @return A {@link NetworkScorerAppData} instance containing information about the
      *         best configured network recommendation provider installed or {@code null}

services/core/java/com/android/server/NetworkScoreService.java

@@ -718,6 +718,15 @@ public class NetworkScoreService extends INetworkScoreService.Stub {
         return null;
     }
 
+    /**
+     * Returns the list of available scorer apps. The list will be empty if there are
+     * no valid scorers.
+     */
+    @Override
+    public List<NetworkScorerAppData> getAllValidScorers() {
+        return mNetworkScorerAppManager.getAllValidScorers();
+    }
+
     @Override
     public void disableScoring() {
         // Only the active scorer or the system should be allowed to disable scoring.