add proguard rules to fix issue in retrofit

proguard-rules.pro

@@ -64,7 +64,21 @@
 -dontwarn retrofit2.KotlinExtensions
 -dontwarn retrofit2.KotlinExtensions$*
 
+
 # With R8 full mode, it sees no subtypes of Retrofit interfaces since they are created with a Proxy
 # and replaces all potential values with null. Explicitly keeping the interfaces prevents this.
 -if interface * { @retrofit2.http.* <methods>; }
 -keep,allowobfuscation interface <1>
+
+# Keep inherited services.
+-if interface * { @retrofit2.http.* <methods>; }
+-keep,allowobfuscation interface * extends <1>
+
+# With R8 full mode generic signatures are stripped for classes that are not
+# kept. Suspend functions are wrapped in continuations where the type argument
+# is used.
+-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation
+
+# R8 full mode strips generic signatures from return types if not kept.
+-if interface * { @retrofit2.http.* public *** *(...); }
+-keep,allowoptimization,allowshrinking,allowobfuscation class <3>