Finish up Intent identifier implementation.

- Add protobuf field.
- Fix documentation.

Fixes: 130365291
Fixes: 130802990
Test: manual
Change-Id: I851c220ec85e73f5bba55390a43304ee4805d0f9

core/java/android/content/Intent.java

@@ -39,7 +39,6 @@ import android.content.pm.ShortcutInfo;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.graphics.Rect;
-import android.media.MediaScannerConnection;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
@@ -8609,6 +8608,13 @@ public class Intent implements Parcelable, Cloneable {
      * fields, the identifier is <em>never</em> used for matching against an {@link IntentFilter};
      * it is as if the identifier has not been set on the Intent.
      *
+     * <p>This can be used, for example, to make this Intent unique from other Intents that
+     * are otherwise the same, for use in creating a {@link android.app.PendingIntent}.  (Be aware
+     * however that the receiver of the PendingIntent will see whatever you put in here.)  The
+     * structure of this string is completely undefined by the platform, however if you are going
+     * to be exposing identifier strings across different applications you may need to define
+     * your own structure if there is no central party defining the contents of this field.</p>
+     *
      * @param identifier The identifier for this Intent.  The contents of the string have no
      *                   meaning to the system, except whether they are exactly the same as
      *                   another identifier.
@@ -10181,6 +10187,9 @@ public class Intent implements Parcelable, Cloneable {
         if (mType != null) {
             proto.write(IntentProto.TYPE, mType);
         }
+        if (mIdentifier != null) {
+            proto.write(IntentProto.IDENTIFIER, mIdentifier);
+        }
         if (mFlags != 0) {
             proto.write(IntentProto.FLAG, "0x" + Integer.toHexString(mFlags));
         }

core/proto/android/content/intent.proto

@@ -23,7 +23,7 @@ import "frameworks/base/core/proto/android/content/component_name.proto";
 import "frameworks/base/core/proto/android/os/patternmatcher.proto";
 import "frameworks/base/core/proto/android/privacy.proto";
 
-// Next Tag: 13
+// Next Tag: 14
 message IntentProto {
     option (.android.msg_privacy).dest = DEST_AUTOMATIC;
 
@@ -62,6 +62,7 @@ message IntentProto {
     // UserHandle value (similar to user_id in other protos).
     optional int32 content_user_hint = 11;
     optional string selector = 12;
+    optional string identifier = 13 [ (.android.privacy).dest = DEST_EXPLICIT ];
 }
 
 // Next Tag: 11