Fix genHiddenConstructor missing @hide

Test: run on AppOpsManager, ensure ctr hidden
Change-Id: I691628d04664b5d9e871fdeadb32455bfda8b158
diff --git a/tools/codegen/src/com/android/codegen/Generators.kt b/tools/codegen/src/com/android/codegen/Generators.kt
index 6c6d011..5fc800b 100644
--- a/tools/codegen/src/com/android/codegen/Generators.kt
+++ b/tools/codegen/src/com/android/codegen/Generators.kt
@@ -5,8 +5,6 @@
 import com.github.javaparser.ast.body.VariableDeclarator
 import com.github.javaparser.ast.expr.AnnotationExpr
 import com.github.javaparser.ast.expr.ArrayInitializerExpr
-import com.github.javaparser.ast.expr.LiteralExpr
-import com.github.javaparser.ast.expr.UnaryExpr
 import java.io.File
 
 
@@ -163,7 +161,12 @@
         return
     }
 
-    +"/** Copy constructor */"
+    +"/**"
+    +" * Copy constructor"
+    if (FeatureFlag.COPY_CONSTRUCTOR.hidden) {
+        +" * @hide"
+    }
+    +" */"
     +GENERATED_MEMBER_HEADER
     "public $ClassName(@$NonNull $ClassName orig)" {
         fields.forEachApply {
diff --git a/tools/codegen/src/com/android/codegen/SharedConstants.kt b/tools/codegen/src/com/android/codegen/SharedConstants.kt
index 2e176c3..6a635d0 100644
--- a/tools/codegen/src/com/android/codegen/SharedConstants.kt
+++ b/tools/codegen/src/com/android/codegen/SharedConstants.kt
@@ -1,7 +1,7 @@
 package com.android.codegen
 
 const val CODEGEN_NAME = "codegen"
-const val CODEGEN_VERSION = "1.0.20"
+const val CODEGEN_VERSION = "1.0.21"
 
 const val CANONICAL_BUILDER_CLASS = "Builder"
 const val BASE_BUILDER_CLASS = "BaseBuilder"