Fix CellBroadcastSetting launchMode and back arrow.

Change CellBroadcastSetting luanchMode from singleTask to standard,
so that it launches in same task when opened from Settings.
Add back arrow button in CellBroadcastSetting action bar.

Bug: 64125910
Test: Manual
Change-Id: Id91622c1fc143f7536d508795a43931f3e33b815

2 files changed, 19 insertions, 1 deletions

diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index e7407ac2a..4972533ff 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -83,7 +83,6 @@
         <activity android:name="CellBroadcastSettings"
                   android:theme="@style/CellBroadcastSettingsTheme"
                   android:label="@string/sms_cb_settings"
-                  android:launchMode="singleTask"
                   android:exported="true" />
 
         <activity android:name="CellBroadcastAlertDialog"
diff --git a/src/com/android/cellbroadcastreceiver/CellBroadcastSettings.java b/src/com/android/cellbroadcastreceiver/CellBroadcastSettings.java
index 7a19febe7..c843cf162 100644
--- a/src/com/android/cellbroadcastreceiver/CellBroadcastSettings.java
+++ b/src/com/android/cellbroadcastreceiver/CellBroadcastSettings.java
@@ -16,6 +16,7 @@
 
 package com.android.cellbroadcastreceiver;
 
+import android.app.ActionBar;
 import android.app.Activity;
 import android.app.Fragment;
 import android.app.backup.BackupManager;
@@ -35,6 +36,7 @@ import android.support.v7.preference.TwoStatePreference;
 import android.telephony.CarrierConfigManager;
 import android.telephony.SubscriptionManager;
 import android.util.Log;
+import android.view.MenuItem;
 
 /**
  * Settings activity for the cell broadcast receiver.
@@ -101,6 +103,12 @@ public class CellBroadcastSettings extends Activity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        ActionBar actionBar = getActionBar();
+        if (actionBar != null) {
+            // android.R.id.home will be triggered in onOptionsItemSelected()
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+
         UserManager userManager = (UserManager) getSystemService(Context.USER_SERVICE);
         if (userManager.hasUserRestriction(UserManager.DISALLOW_CONFIG_CELL_BROADCASTS)) {
             setContentView(R.layout.cell_broadcast_disallowed_preference_screen);
@@ -115,6 +123,17 @@ public class CellBroadcastSettings extends Activity {
         }
     }
 
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            // Respond to the action bar's Up/Home button
+            case android.R.id.home:
+                finish();
+                return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
     /**
      * New fragment-style implementation of preferences.
      */