Hmm, I did post a response but it seems that my posts are hidden for some reason. Either because attachments or screenshots need to be verified first.
But to recap what I did, I found so far that I just needed a custom Manifest file. This can be checked in Publishing settings and adds An Android Manifest file to Plugins folder.
Below is what worked for me.
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
package="com.unity3d.player"
xmlns:tools="http://schemas.android.com/tools">
<application>
<activity android:name="com.unity3d.player.UnityPlayerActivity"
android:theme="@style/UnityThemeSelector"
android:launchMode="singleTask"
android:configChanges="orientation|keyboardHidden"
android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
<category android:name="com.htc.intent.category.VRAPP" />
</intent-filter>
<meta-data android:name="unityplayer.UnityActivity" android:value="true" />
<meta-data android:name="com.htc.vr.content.NumDoFHmd" android:value="6DoF"/>
<meta-data android:name="com.htc.vr.content.NumDoFController" android:value="6DoF"/>
<meta-data android:name="com.htc.vr.content.NumController" android:value="2"/>
</activity>
</application>
</manifest>