Private visibility for non-const, non-jvmField class companion property backing field

plugins/android-compiler-plugin/testData/codegen/android/singleFile/0.kt

@@ -8,12 +8,12 @@ import kotlinx.android.synthetic.main.layout.*
 class R {
     class id {
         companion object {
-            val item_detail_container = 0
-            val textView1 = 1
-            val password = 2
-            val textView2 = 3
-            val passwordConfirmation = 4
-            val login = 5
+            const val item_detail_container = 0
+            const val textView1 = 1
+            const val password = 2
+            const val textView2 = 3
+            const val passwordConfirmation = 4
+            const val login = 5
         }
     }
 }

plugins/android-compiler-plugin/testData/codegen/android/singleFile/1.kt

@@ -8,12 +8,12 @@ import kotlinx.android.synthetic.main.layout.*
 class R {
     class id {
         companion object {
-            val item_detail_container = 0
-            val textView1 = 1
-            val password = 2
-            val textView2 = 3
-            val passwordConfirmation = 4
-            val login = 5
+            const val item_detail_container = 0
+            const val textView1 = 1
+            const val password = 2
+            const val textView2 = 3
+            const val passwordConfirmation = 4
+            const val login = 5
         }
     }
 }