android: do not embed firebase-analytics

Change-Id: I0fee34c7c21ca6ad13514d48fc9c5600b06f6d96
diff --git a/ring-android/app/proguard-rules.pro b/ring-android/app/proguard-rules.pro
index 12dd49c..ca2db8f 100644
--- a/ring-android/app/proguard-rules.pro
+++ b/ring-android/app/proguard-rules.pro
@@ -17,6 +17,7 @@
 # Firebase
 -keep class com.firebase.** { *; }
 -keep class com.google.firebase.** { *; }
+-dontwarn com.google.firebase.analytics.connector.AnalyticsConnector
 
 # ORMLite
 -keep class com.j256.**