Remove the comment that says the performance hint manager must be released after use.

This is not true. The performance hint manager is a global singleton and does not need to be released.

Flag: DOCS_ONLY
Test: n/a
Bug: 357214902

Change-Id: I82c694aaa78bd2ae70f493c4be3d9cd7970bcc8c
diff --git a/include/android/performance_hint.h b/include/android/performance_hint.h
index 8736695..3f32a5a 100644
--- a/include/android/performance_hint.h
+++ b/include/android/performance_hint.h
@@ -85,7 +85,6 @@
 
 /**
  * An opaque type representing a handle to a performance hint manager.
- * It must be released after use.
  *
  * To use:<ul>
  *    <li>Obtain the performance hint manager instance by calling