Revert "Add library retargeting classes into retarget package"

This reverts commit 9f85fa9d92492aed7a4318241662da15a1e1eb37.

Reason for revert: Bot failures

Change-Id: I770e4ebf9e64892bef0c431552696ae28c42c21b
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java b/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
index 5b505fa..3dc74ac 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
@@ -64,7 +64,6 @@
 
 public class DesugaredLibraryRetargeter {
 
-  public static final String RETARGET_PACKAGE = "retarget/";
   public static final String DESUGAR_LIB_RETARGET_CLASS_NAME_PREFIX =
       "$r8$retargetLibraryMember$virtualDispatch";
 
@@ -676,7 +675,6 @@
                 .options()
                 .desugaredLibraryConfiguration
                 .getSynthesizedLibraryClassesPackagePrefix()
-            + RETARGET_PACKAGE
             + DESUGAR_LIB_RETARGET_CLASS_NAME_PREFIX
             + '$'
             + method.getHolderType().getName()