Keep class name for class with generated code

The test which checks that code was fully generated relies on the
name not changing in r8lib.

Bug: b/264256610
Change-Id: I1eee7d53bb88f47c4623eaf8f6bbb8b45d308400

src/main/keep.txt

diff --git a/src/main/keep.txt b/src/main/keep.txt
index 689e5b5..2213ce9 100644
--- a/src/main/keep.txt
+++ b/src/main/keep.txt
@@ -49,3 +49,5 @@
 -keep class com.android.tools.r8.jetbrains.kotlin.SafePublicationLazyImpl {
   java.lang.Object getValue();
 }
+# Test in this class is using the class name to fing the original .java file.
+-keep class com.android.tools.r8.ir.desugar.varhandle.VarHandleDesugaringMethods