New BillingCycleRepository

Migrate BillingCyclePreference to BillingCycleRepository first, will
also migrate DataUsageList in future cl.

Also fix an issue that the BillingCyclePreference initial enable state
not set.

Bug: 290856342
Test: manual - on mobile settings
Test: unit test
Change-Id: Idd171fefbc30763010afb7bfb68543612f7b9b1a

src/com/android/settings/datausage/lib/BillingCycleRepository.kt

@@ -0,0 +1,53 @@
+/*
+ * 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.datausage.lib
+
+import android.content.Context
+import android.os.INetworkManagementService
+import android.os.ServiceManager
+import android.telephony.TelephonyManager
+import android.util.Log
+import com.android.settingslib.spaprivileged.framework.common.userManager
+
+class BillingCycleRepository(
+    context: Context,
+    private val networkService: INetworkManagementService =
+        INetworkManagementService.Stub.asInterface(
+            ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE)
+        ),
+) {
+    private val userManager = context.userManager
+    private val telephonyManager = context.getSystemService(TelephonyManager::class.java)!!
+
+    fun isModifiable(subId: Int): Boolean =
+        isBandwidthControlEnabled() && userManager.isAdminUser && isDataEnabled(subId)
+
+    fun isBandwidthControlEnabled(): Boolean = try {
+        networkService.isBandwidthControlEnabled
+    } catch (e: Exception) {
+        Log.w(TAG, "problem talking with INetworkManagementService: ", e)
+        false
+    }
+
+    private fun isDataEnabled(subId: Int): Boolean =
+        telephonyManager.createForSubscriptionId(subId)
+            .isDataEnabledForReason(TelephonyManager.DATA_ENABLED_REASON_USER)
+
+    companion object {
+        private const val TAG = "BillingCycleRepository"
+    }
+}