wifi: Return SoftApConfiguration for cloud restore.

Restore process might need to notify user because
restored ap configuration requires the band conversion.

Bug: 142752869
Test: frameworks/base/wifi/tests/
Change-Id: I409a4533f8feccc888f4b605fb9466e3be0b2e89
diff --git a/api/system-current.txt b/api/system-current.txt
index 6b51eab..1497e00 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -5660,10 +5660,10 @@
     method @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public void registerTrafficStateCallback(@NonNull java.util.concurrent.Executor, @NonNull android.net.wifi.WifiManager.TrafficStateCallback);
     method @RequiresPermission(android.Manifest.permission.WIFI_UPDATE_USABILITY_STATS_SCORE) public void removeOnWifiUsabilityStatsListener(@NonNull android.net.wifi.WifiManager.OnWifiUsabilityStatsListener);
     method @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public void restoreBackupData(@NonNull byte[]);
-    method @Nullable @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public void restoreSoftApBackupData(@NonNull byte[]);
+    method @Nullable @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public android.net.wifi.SoftApConfiguration restoreSoftApBackupData(@NonNull byte[]);
     method @Deprecated @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public void restoreSupplicantBackupData(@NonNull byte[], @NonNull byte[]);
     method @NonNull @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public byte[] retrieveBackupData();
-    method @Nullable @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public byte[] retrieveSoftApBackupData();
+    method @NonNull @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public byte[] retrieveSoftApBackupData();
     method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_SETUP_WIZARD, android.Manifest.permission.NETWORK_STACK}) public void save(@NonNull android.net.wifi.WifiConfiguration, @Nullable android.net.wifi.WifiManager.ActionListener);
     method @RequiresPermission(android.Manifest.permission.WIFI_SET_DEVICE_MOBILITY_STATE) public void setDeviceMobilityState(int);
     method @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS) public boolean setSoftApConfiguration(@NonNull android.net.wifi.SoftApConfiguration);
diff --git a/wifi/java/android/net/wifi/IWifiManager.aidl b/wifi/java/android/net/wifi/IWifiManager.aidl
index b52880e..46efdd6 100644
--- a/wifi/java/android/net/wifi/IWifiManager.aidl
+++ b/wifi/java/android/net/wifi/IWifiManager.aidl
@@ -186,7 +186,7 @@
 
     byte[] retrieveSoftApBackupData();
 
-    void restoreSoftApBackupData(in byte[] data);
+    SoftApConfiguration restoreSoftApBackupData(in byte[] data);
 
     void restoreSupplicantBackupData(in byte[] supplicantData, in byte[] ipConfigData);
 
diff --git a/wifi/java/android/net/wifi/WifiManager.java b/wifi/java/android/net/wifi/WifiManager.java
index 50d62a0..3bcad2f 100644
--- a/wifi/java/android/net/wifi/WifiManager.java
+++ b/wifi/java/android/net/wifi/WifiManager.java
@@ -4686,10 +4686,13 @@
     }
 
     /**
-     * Retrieve the soft ap config data to be backed to save current config data.
+     * Returns a byte stream representing the data that needs to be backed up to save the
+     * current soft ap config data.
+     *
+     * This soft ap config can be restored by calling {@link #restoreSoftApBackupData(byte[])}
      * @hide
      */
-    @Nullable
+    @NonNull
     @SystemApi
     @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS)
     public byte[] retrieveSoftApBackupData() {
@@ -4701,15 +4704,17 @@
     }
 
     /**
-     * Restore soft ap config from the backed up data.
+     * Returns soft ap config from the backed up data.
+     * @param data byte stream in the same format produced by {@link #retrieveSoftApBackupData()}
+     *
      * @hide
      */
     @Nullable
     @SystemApi
     @RequiresPermission(android.Manifest.permission.NETWORK_SETTINGS)
-    public void restoreSoftApBackupData(@NonNull byte[] data) {
+    public SoftApConfiguration restoreSoftApBackupData(@NonNull byte[] data) {
         try {
-            mService.restoreSoftApBackupData(data);
+            return mService.restoreSoftApBackupData(data);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/wifi/java/com/android/server/wifi/BaseWifiService.java b/wifi/java/com/android/server/wifi/BaseWifiService.java
index 524a53c..86392fa 100644
--- a/wifi/java/com/android/server/wifi/BaseWifiService.java
+++ b/wifi/java/com/android/server/wifi/BaseWifiService.java
@@ -28,7 +28,6 @@
 import android.net.wifi.IOnWifiActivityEnergyInfoListener;
 import android.net.wifi.IOnWifiUsabilityStatsListener;
 import android.net.wifi.IScanResultsCallback;
-import android.net.wifi.IScanResultsListener;
 import android.net.wifi.ISoftApCallback;
 import android.net.wifi.ISuggestionConnectionStatusListener;
 import android.net.wifi.ITrafficStateCallback;
@@ -414,7 +413,7 @@
     }
 
     @Override
-    public void restoreSoftApBackupData(byte[] data) {
+    public SoftApConfiguration restoreSoftApBackupData(byte[] data) {
         throw new UnsupportedOperationException();
     }