add proguard rules

Author: bklastaitis-branch

AdobeBranchExtension/proguard-rules.pro

@@ -3,4 +3,7 @@
 
 # for Huawei devices without GMS (Branch looks up oaid via refelection)
 #-keep class com.huawei.hms.ads.** { *; }
-#-keep interface com.huawei.hms.ads.** { *; }
+#-keep interface com.huawei.hms.ads.** { *; }
+
+-keep class io.branch.adobe.extension.** { *; }
+-keep interface io.branch.adobe.extension.** { *; }