Don't expect desugared library companion classes to be present when collecting single jar

Any class in the desugared library should be considered a library class and will
not be generated during desugaring and therefore not present in the single jar
collected. It will be present in the desugared library which will be on classpath
at runtime.

RELNOTES: None
PiperOrigin-RevId: 330334214

src/tools/android/java/com/google/devtools/build/android/r8/desugar/OutputConsumer.java

diff --git a/src/tools/android/java/com/google/devtools/build/android/r8/desugar/OutputConsumer.java b/src/tools/android/java/com/google/devtools/build/android/r8/desugar/OutputConsumer.java
index bf94ebd..e2fe1f6 100644
--- a/src/tools/android/java/com/google/devtools/build/android/r8/desugar/OutputConsumer.java
+++ b/src/tools/android/java/com/google/devtools/build/android/r8/desugar/OutputConsumer.java
@@ -177,7 +177,11 @@
             return;
           }
           if (DescriptorUtils.isCompanionClassBinaryName(owner)) {
-            dependencyCollector.assumeCompanionClass(className, owner);
+            // Don't expect companion classes from the desugared library to be present. They are
+            // considered library classes not program classes.
+            if (!owner.startsWith("j$")) {
+              dependencyCollector.assumeCompanionClass(className, owner);
+            }
           }
         }
       }