Needed to remove an intent-filter for an activity that was defined in a library. This can be done by instructing the Android Manifest Merger with a tools:node="remove" on the intent-filter tag.

To identify a specific intent-filter tag (there can be many), the merger uses the combination of android:name attributes from the child action and category tags.

Example:

<activity
  android:name=".SomeActivity">
  <intent-filter tools:node="remove">
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER"/>
  </intent-filter>
</activity>