[Settings] replace isNonTtyOrTtyOnVolteEnabled() in WFC

1. Code refactor
2. Replace ImsManager#isNonTtyOrTtyOnVolteEnabled() by combination of
   TelecomManager#getCurrentTtyMode() and
   ImsMmTelManager#isTtyOverVolteEnabled()

Bug: 140542283
Test: manual
Change-Id: Ia5179ee1a23f054899bc74c796542bae40cdc8d5

src/com/android/settings/network/ims/ImsQuery.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2020 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.network.ims;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.RejectedExecutionException;
+
+
+/**
+ * An interface for querying IMS, and return {@code Future<Boolean>}
+ */
+public interface ImsQuery {
+
+    /**
+     * Interface for performing IMS status/configuration query through ExecutorService
+     *
+     * @param executors {@code ExecutorService} which allows to submit {@code ImsQuery} when
+     * required
+     * @return result of query in format of {@code Future<Boolean>}
+     */
+    Future<Boolean> query(ExecutorService executors) throws RejectedExecutionException;
+
+}