fix: Missing Proguard rules for R8 in full mode (#1196)

Author: azlekov

parse/release-proguard.pro

@@ -1,7 +1,13 @@
+-keep @com.parse.ParseClassName class com.parse.*
 -keepnames class com.parse.** { *; }
+-keepclassmembers public class * extends com.parse.** {
+   public <init>(...);
+}
 
 # Required for Parse
 -keepattributes *Annotation*
 -keepattributes Signature
-# https://github.com/square/okio#proguard
--dontwarn okio.**
+
+# Retracing stacktraces
+-keepattributes LineNumberTable,SourceFile
+-renamesourcefileattribute SourceFile