Addressed review comments

gson/src/main/resources/META-INF/proguard/gson.pro

@@ -22,6 +22,7 @@
 # Keep class TypeToken (respectively its generic signature) if present
 -if class com.google.gson.reflect.TypeToken
 -keep,allowobfuscation class com.google.gson.reflect.TypeToken
+#-keep class com.google.gson.reflect.TypeToken { *; }
 
 # Keep any (anonymous) classes extending TypeToken
 -keep,allowobfuscation class * extends com.google.gson.reflect.TypeToken
@@ -54,16 +55,19 @@
   <init>();
 }
 
-# Keep fields annotated with @SerializedName for classes which are present.
+# Keep fields annotated with @SerializedName for classes which are referenced.
 # If classes with fields annotated with @SerializedName have a no-args
-# constructor keep that as well.
+# constructor keep that as well. Based on
+# https://issuetracker.google.com/issues/150189783#comment11.
+# See also https://github.com/google/gson/pull/2420#discussion_r1241813541
+# for a more detailed explanation.
 -if class *
 -keepclasseswithmembers,allowobfuscation class <1> {
   @com.google.gson.annotations.SerializedName <fields>;
 }
 -if class * {
   @com.google.gson.annotations.SerializedName <fields>;
 }
--keepclassmembers,allowobfuscation class <1> {
+-keepclassmembers,allowobfuscation,allowoptimization class <1> {
   <init>();
 }

shrinker-test/common.pro

@@ -38,3 +38,5 @@
 -keepclassmembernames class com.example.ClassWithVersionAnnotations {
   <fields>;
 }
+
+-dontobfuscate

shrinker-test/proguard.pro

@@ -12,9 +12,3 @@
 -keepclassmembernames class com.example.NoSerializedNameMain$TestClassNotAbstract {
   <fields>;
 }
--keepclassmembernames class com.example.NoSerializedNameMain$TestClassWithoutDefaultConstructor {
-  <fields>;
-}
-#-keep class com.example.ClassWithSerializedName {
-#  <init>(...);
-#}