How do I change the app icon in the 'Recents' Screen?

I know how to change the icon of my app, but when I look at the Recents Screen, the icon is the default one.

App icon (all good so far):

Icon in my Recents Screen:

This is the 'application' tag of my 'AndroidManifest.xml'

<application
    android:name=".App"
    android:allowBackup="true"
    android:icon="@mipmap/iconout"
    android:roundIcon="@mipmap/iconout"
    android:logo="@mipmap/iconout"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

I've tried many solutions that I found on this platorm (that didn't work), like:

1. file->new->image asset->choose image..
2. install & unistall the app
3. build & clean project
4. delete all the default icons on my project
5. drag & drop my icon to drawable from mipmap folder

Any other possible solutions? Thank you in advance!

Ok I found the solution and decided to answer for anyone that will encounter the same problem in the future.

I fixed it by adding android:icon="@mipmap/iconout" in the main activity tag declaration in the AndroidManifest.xml, like so:

<activity
        android:icon="@mipmap/iconout"
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

And here's the final result: