Switch to production constant for v2 signing scheme ID.

Bug: 25794543

(cherry picked from commit 97dd58a071c16c31ab2ce3f29f8fa7e2db7c8b52)

Change-Id: Iefb8eec4e512115bc6a0f5126249e8b2c8b66ddb
diff --git a/tools/signapk/src/com/android/signapk/ApkSignerV2.java b/tools/signapk/src/com/android/signapk/ApkSignerV2.java
index ee5e72e..46cd11e 100644
--- a/tools/signapk/src/com/android/signapk/ApkSignerV2.java
+++ b/tools/signapk/src/com/android/signapk/ApkSignerV2.java
@@ -85,8 +85,7 @@
      * <p>The attribute contains a comma-separated set of signature scheme IDs.
      */
     public static final String SF_ATTRIBUTE_ANDROID_APK_SIGNED_NAME = "X-Android-APK-Signed";
-    // TODO: Adjust the value when signing scheme finalized.
-    public static final String SF_ATTRIBUTE_ANDROID_APK_SIGNED_VALUE = "1234567890";
+    public static final String SF_ATTRIBUTE_ANDROID_APK_SIGNED_VALUE = "2";
 
     private static final int CONTENT_DIGEST_CHUNKED_SHA256 = 0;
     private static final int CONTENT_DIGEST_CHUNKED_SHA512 = 1;