Vungle SDK Version: android 4.0.3
Admob Unity Plugin Version: Unity plugin 3.3.0

1. Set Vungle as a net source for your app id on Admob Dashboard.

2.Coding for request Ad and play an ad.

3. Put Vungle SDK into your unity project.

3.1 Vungle Adapter and SDK 4.0.3 into Assets/Plugins/Android/GoogleMobileAdsPlugin/libs

VungleAdapter.aar
Vungle Android SDK4.0.3
- vungle-publisher-adaptive-id-4.0.3.jar
- dagger-2.7.jar
- javax.inject-1.jar

3.2 Android Manifest with the new following activities:

<activity android:name="com.vungle.publisher.VideoFullScreenAdActivity"
  android:configChanges="keyboardHidden|orientation|screenSize|screenLayout|smallestScreenSize"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"/>
<activity android:name="com.vungle.publisher.MraidFullScreenAdActivity"
android:configChanges="keyboardHidden|orientation|screenSize|screenLayout|smallestScreenSize"
        android:theme="@android:style/Theme.Translucent.NoTitleBar.Fullscreen"/>

4. BUT we have to do the following additional steps as the VungleAdapter.aar is NOT working.

- Remove the VungleAdapter.aar file and decompile it.
- Extract out classes.jar from the decompilation.
- Rename classes.jar to VungleAdapter.jar and place it where VungleAdapter.aar would be.