Add @UnsupportedAppUsage annotations

For packages:
  android.security.net.config
  android.security.keystore
  android.security.keymaster
  android.security

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: Ifed4da56531195f64fd53d84f14b4e8298843b2c
Merged-In: I7762dd647bede8abc9be2c538af3a3a99a25a73e
diff --git a/keystore/java/android/security/Credentials.java b/keystore/java/android/security/Credentials.java
index 57db20b..7216a22 100644
--- a/keystore/java/android/security/Credentials.java
+++ b/keystore/java/android/security/Credentials.java
@@ -16,6 +16,7 @@
 
 package android.security;
 
+import android.annotation.UnsupportedAppUsage;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
@@ -172,6 +173,7 @@
 
     private static Credentials singleton;
 
+    @UnsupportedAppUsage
     public static Credentials getInstance() {
         if (singleton == null) {
             singleton = new Credentials();
@@ -179,6 +181,7 @@
         return singleton;
     }
 
+    @UnsupportedAppUsage
     public void unlock(Context context) {
         try {
             Intent intent = new Intent(UNLOCK_ACTION);
@@ -197,6 +200,7 @@
         }
     }
 
+    @UnsupportedAppUsage
     public void install(Context context, KeyPair pair) {
         try {
             Intent intent = KeyChain.createInstallIntent();
@@ -208,6 +212,7 @@
         }
     }
 
+    @UnsupportedAppUsage
     public void install(Context context, String type, byte[] value) {
         try {
             Intent intent = KeyChain.createInstallIntent();