Android Manifest Documentation discrepancies

[jeffsteinmetz]

In the sample application, is there any documentation as to why android.permission.SYSTEM_ALERT_WINDOW is required as a permission?

https://github.com/invertase/react-native-firebase-starter/blob/master/android/app/src/main/AndroidManifest.xml#L7

It is not listed in the docs
https://rnfirebase.io/docs/v5.x.x/notifications/android

In the docs, it recommends adding the following

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
 <uses-permission android:name="android.permission.VIBRATE" />

It also appears RECEIVE_BOOT_COMPLETED and VIBRATE are not shown in the sample application.
Is there an example for RECEIVE_BOOT_COMPLETED and VIBRATE used (per the docs vs sample app?)

Also the docs suggest this in android/app/src/main/AndroidManifest.xml

<activity
  ...
  android:launchMode="singleTop"
>

Is there any location in the docs or sample app that clarify the different Android manifest configs?