Remove TODO for not marking parent pacakges as used

Bug: 178563208
Change-Id: I51f3f5d09d9b2bc9d695bf388de2a8d6db43b469

src/main/java/com/android/tools/r8/naming/ClassNameMinifier.java

diff --git a/src/main/java/com/android/tools/r8/naming/ClassNameMinifier.java b/src/main/java/com/android/tools/r8/naming/ClassNameMinifier.java
index e6937ea..1b91b62 100644
--- a/src/main/java/com/android/tools/r8/naming/ClassNameMinifier.java
+++ b/src/main/java/com/android/tools/r8/naming/ClassNameMinifier.java
@@ -196,8 +196,6 @@
   private void registerPackagePrefixesAsUsed(String packagePrefix) {
     String usedPrefix = packagePrefix;
     while (usedPrefix.length() > 0) {
-      // Only reserve the actual package and not all parent packages.
-      // TODO(b/178563208): Only mark prefix as used if usedPrefix.equals(packagePrefix)
       usedPackagePrefixes.add(usedPrefix);
       states.computeIfAbsent(usedPrefix, Namespace::new);
       usedPrefix = getParentPackagePrefix(usedPrefix);