Missing app icon in android studio

I have this layout, I placed the line android:icon="@drawable/ic_launcher", but the app icon is still missing.

In the manifest is also place inside the activity.

Layout:

<RelativeLayout
    xmlns:android="http://ift.tt/nIICcg"
    xmlns:tools="http://ift.tt/LrGmb4"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".java0"
    tools:ignore="MergeRootFrame"
    android:screenOrientation="portrait"
    android:icon="@drawable/ic_launcher"
    android:background="#ffff7e00">
</RelativeLayout>
Manifest:

<activity
            android:screenOrientation="portrait"
            android:name=".java0"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>