Refer to the last Hotspot password when generating the password

- Query the last Hotspot password when security type is SECURITY_TYPE_OPEN and it will be used when the user changes to another security type

- If the last hotspot password is an empty string, then generate random password

Bug: 201789473
Test: manual test
atest -c WifiHotspotRepositoryTest
make RunSettingsRoboTests ROBOTEST_FILTER=WifiTetherPasswordPreferenceControllerTest

Change-Id: Id3a846099238433e7b6c8b934fa26a74df0dcb61

src/com/android/settings/wifi/factory/WifiFeatureProvider.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.wifi.factory;
+
+import android.content.Context;
+import android.net.wifi.WifiManager;
+
+import androidx.annotation.NonNull;
+
+import com.android.settings.wifi.repository.WifiHotspotRepository;
+
+/**
+ * Wi-Fi Feature Provider
+ */
+public class WifiFeatureProvider {
+
+    private final Context mAppContext;
+    private WifiManager mWifiManager;
+    private WifiHotspotRepository mWifiHotspotRepository;
+
+    public WifiFeatureProvider(@NonNull Context appContext) {
+        mAppContext = appContext;
+    }
+
+    /**
+     * Get WifiManager
+     */
+    public WifiManager getWifiManager() {
+        if (mWifiManager == null) {
+            mWifiManager = mAppContext.getSystemService(WifiManager.class);
+        }
+        return mWifiManager;
+    }
+
+    /**
+     * Get WifiRepository
+     */
+    public WifiHotspotRepository getWifiHotspotRepository() {
+        if (mWifiHotspotRepository == null) {
+            mWifiHotspotRepository = new WifiHotspotRepository(mAppContext, getWifiManager());
+        }
+        return mWifiHotspotRepository;
+    }
+}
+