Add @UnsupportedAppUsage annotations

For packages:
  android.mtp

This is an automatically generated CL. See go/UnsupportedAppUsage
for more details.

Exempted-From-Owner-Approval: Mechanical changes to the codebase
which have been approved by Android API council and announced on
android-eng@

Bug: 110868826
Test: m
Change-Id: Id97d70dc1003cd7c6ed585d647bf0df0fd7a946a
diff --git a/media/java/android/mtp/MtpStorage.java b/media/java/android/mtp/MtpStorage.java
index 2625e0c..c714b3c 100644
--- a/media/java/android/mtp/MtpStorage.java
+++ b/media/java/android/mtp/MtpStorage.java
@@ -16,6 +16,7 @@
 
 package android.mtp;
 
+import android.annotation.UnsupportedAppUsage;
 import android.os.storage.StorageVolume;
 
 /**
@@ -46,6 +47,7 @@
      *
      * @return the storage ID
      */
+    @UnsupportedAppUsage
     public final int getStorageId() {
         return mStorageId;
     }
@@ -55,6 +57,7 @@
      *
      * @return the storage file path
      */
+    @UnsupportedAppUsage
     public final String getPath() {
         return mPath;
     }