Update README.md

Author: Brie

Diff for: README.md

@@ -11,9 +11,11 @@ Firebase Analytics integration for [analytics-android](https://github.com/segmen
 To install the Segment-Firebase integration, simply add this line to your gradle file:
 
 ```
-compile 'com.segment.analytics.android.integrations:firebase:+'
+implementation 'com.segment.analytics.android.integrations:firebase:+@aar'
 ```
 
+**Note:** The Firebase SDK requires Android resources. To avoid issues with app crashes please implement using the `aar` package. 
+
 ### Note
 To use firebase-integrations 1.4.+ :
 * `Update your app to use (AndroidX) or Android 29`