Update Proguard rules for R8 fullmode
Taken from here
-# Retrofit does reflection on generic parameters and InnerClass is required to use Signature.
--keepattributes Signature, InnerClasses
+# Retrofit does reflection on generic parameters. InnerClasses is required to use Signature and
+# EnclosingMethod is required to use InnerClasses.
+-keepattributes Signature, InnerClasses, EnclosingMethod
# Retain service method parameters when optimizing.
-keepclassmembers,allowshrinking,allowobfuscation interface * {
