Add TARE button and homepage to developer options.

A TARE button is needed in the developer options in settings to allow
users and developers to change the default settings it will come with.
When clicked, it opens an activity of the TARE homepage with a toggle
and the two policies (Alarm Manager and Job Scheduler) to choose between. It also contains a revert to default settings button.

Bug: 191876567

Test: Manual (open Settings > System > Developer Options > TARE and
verify tabs and menus are there)

Change-Id: Id14bc9c1dcbaaf2aeb74ba7efb0168ab424f5d0c

src/com/android/settings/development/tare/TareHomePage.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2021 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.development.tare;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Button;
+import android.widget.CompoundButton;
+import android.widget.CompoundButton.OnCheckedChangeListener;
+import android.widget.Switch;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import com.android.settings.R;
+
+/** Class for creating the TARE homepage in settings*/
+public class TareHomePage extends Activity {
+    private Switch mOnSwitch;
+    private Button mRevButton;
+    private TextView mAlarmManagerView;
+    private TextView mJobSchedulerView;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.tare_homepage);
+
+        mOnSwitch = findViewById(R.id.on_switch);
+        mRevButton = findViewById(R.id.revert_button);
+        mAlarmManagerView = findViewById(R.id.alarm_manager);
+        mJobSchedulerView = findViewById(R.id.job_scheduler);
+
+        // TODO: Set the status of the buttons based on the current status
+
+        mOnSwitch.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                mRevButton.setEnabled(isChecked);
+                mAlarmManagerView.setEnabled(isChecked);
+                mJobSchedulerView.setEnabled(isChecked);
+            }
+        });
+    }
+
+    /** This method should revert the TARE settings to the original default settings */
+    // TODO: Establish default TARE values and make this method revert all settings back to default
+    public void revertSettings(View v) {
+        Toast.makeText(this, R.string.tare_settings_reverted_toast, Toast.LENGTH_LONG).show();
+    }
+}