Merge "libbinder_ndk: clarify descriptor encoding" am: fe46e48ea9 am: 8523bb984a am: e9920739a2

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/1674668

Change-Id: Icd7f2924fda6fea4fa780aa73e68248fed3fd008
diff --git a/libs/binder/ndk/include_ndk/android/binder_ibinder.h b/libs/binder/ndk/include_ndk/android/binder_ibinder.h
index 787a245..9e2050b 100644
--- a/libs/binder/ndk/include_ndk/android/binder_ibinder.h
+++ b/libs/binder/ndk/include_ndk/android/binder_ibinder.h
@@ -173,7 +173,7 @@
  * Available since API level 29.
  *
  * \param interfaceDescriptor this is a unique identifier for the class. This is used internally for
- * sanity checks on transactions.
+ * validity checks on transactions. This should be utf-8.
  * \param onCreate see AIBinder_Class_onCreate.
  * \param onDestroy see AIBinder_Class_onDestroy.
  * \param onTransact see AIBinder_Class_onTransact.
@@ -645,7 +645,9 @@
  *
  * \return the class descriptor string. This pointer will never be null; a
  * descriptor is required to define a class. The pointer is owned by the class
- * and will remain valid as long as the class does.
+ * and will remain valid as long as the class does. For a local class, this will
+ * be the same value (not necessarily pointer equal) as is passed into
+ * AIBinder_Class_define. Format is utf-8.
  */
 const char* AIBinder_Class_getDescriptor(const AIBinder_Class* clazz) __INTRODUCED_IN(31);