Remove usage of a hidden API (HandlerExecutor).

Test: basic sanity
Bug: 137202333
Change-Id: I88876cc295277f1cbb643fe9520ce7116d352643
Merged-In: I88876cc295277f1cbb643fe9520ce7116d352643
diff --git a/src/java/com/android/ims/HandlerExecutor.java b/src/java/com/android/ims/HandlerExecutor.java
new file mode 100644
index 0000000..5797116
--- /dev/null
+++ b/src/java/com/android/ims/HandlerExecutor.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2019 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.ims;
+
+import android.annotation.NonNull;
+
+import android.os.Handler;
+import com.android.internal.util.Preconditions;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionException;
+
+/**
+ * An adapter {@link Executor} that posts all executed tasks onto the given
+ * {@link Handler}.
+ *
+ * @hide
+ */
+public class HandlerExecutor implements Executor {
+    private final Handler mHandler;
+
+    public HandlerExecutor(@NonNull Handler handler) {
+        mHandler = Preconditions.checkNotNull(handler);
+    }
+
+    @Override
+    public void execute(Runnable command) {
+        if (!mHandler.post(command)) {
+            throw new RejectedExecutionException(mHandler + " is shutting down");
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/java/com/android/ims/ImsManager.java b/src/java/com/android/ims/ImsManager.java
index 56c847e..68bdf12 100644
--- a/src/java/com/android/ims/ImsManager.java
+++ b/src/java/com/android/ims/ImsManager.java
@@ -22,7 +22,6 @@
 import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.os.Handler;
-import android.os.HandlerExecutor;
 import android.os.Looper;
 import android.os.Message;
 import android.os.Parcel;
diff --git a/src/java/com/android/ims/MmTelFeatureConnection.java b/src/java/com/android/ims/MmTelFeatureConnection.java
index 31095c7..ea7d1e1 100644
--- a/src/java/com/android/ims/MmTelFeatureConnection.java
+++ b/src/java/com/android/ims/MmTelFeatureConnection.java
@@ -20,7 +20,6 @@
 import android.annotation.Nullable;
 import android.content.Context;
 import android.os.Handler;
-import android.os.HandlerExecutor;
 import android.os.IBinder;
 import android.os.IInterface;
 import android.os.Looper;