Define trust agent framework components

Adds the TrustManager system service that allows
registering for changes to the trust status and
reporting events that are important to trust agents.

Bug: 13723878
Change-Id: I7d0d2ea86fd755702d31aa5d49cac038a6cd4301
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 2e0ac08..2a4d872 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2547,6 +2547,13 @@
         android:label="@string/permlab_control_keyguard"
         android:description="@string/permdesc_control_keyguard" />
 
+    <!-- Allows an application to listen to trust changes.  Only allowed for system processes.
+        @hide -->
+    <permission android:name="android.permission.TRUST_LISTENER"
+                android:protectionLevel="signature"
+                android:label="@string/permlab_trust_listener"
+                android:description="@string/permdesc_trust_listener" />
+
     <!-- Must be required by an {@link
          android.service.trust.TrustAgentService},
          to ensure that only the system can bind to it. -->