I have an activity 'A' defined in Manifest like below:

```
<activity
    android:name=".A"
    android:launchMode="singleTask"
    android:screenOrientation="portrait">

    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>

</activity>

```

When I launch my APP, that activity is always loaded from the start. It wont start from my prev activity.
When I remove `android:launchMode`, then it works as I expect.