Adding AudioUsage converters to AudioAttributes

audio_policy_configuration.xsd defines strings used by HAL
to represent audio usages. This adds converters between
those strings and the AudioAttributes#attributeUsage values

Bug: 171572311
Test: atest AudioAttributesTest
Change-Id: I5301276ebd6ea1539182e9925a1e19f515e80597
diff --git a/Android.bp b/Android.bp
index bbaeea5..aeee748 100644
--- a/Android.bp
+++ b/Android.bp
@@ -380,6 +380,7 @@
         // etc.
         ":framework-javastream-protos",
         ":statslog-framework-java-gen", // FrameworkStatsLog.java
+        ":audio_policy_configuration_V7_0",
     ],
 }
 
@@ -1352,6 +1353,7 @@
 metalava_framework_docs_args = "--manifest $(location core/res/AndroidManifest.xml) " +
     "--ignore-classes-on-classpath " +
     "--hide-package com.android.server " +
+    "--hide-package android.audio.policy.configuration.V7_0 " +
     "--error UnhiddenSystemApi " +
     "--hide RequiresPermission " +
     "--hide CallbackInterface " +