Add local-only hotspot info into tether state change broadcast

Test: as follows
    - build
    - flashed
    - booted
    - "runtest frameworks-net" passes
    - manually starting tethering shows Settings and icon updates
Bug: 31466854
Bug: 32163131

Change-Id: I938074587dfeec221c5cdb43a392802ad3fc3589
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 111c50a..768beea 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -301,7 +301,8 @@
     /**
      * Broadcast Action: A tetherable connection has come or gone.
      * Uses {@code ConnectivityManager.EXTRA_AVAILABLE_TETHER},
-     * {@code ConnectivityManager.EXTRA_ACTIVE_TETHER} and
+     * {@code ConnectivityManager.EXTRA_ACTIVE_LOCAL_ONLY},
+     * {@code ConnectivityManager.EXTRA_ACTIVE_TETHER}, and
      * {@code ConnectivityManager.EXTRA_ERRORED_TETHER} to indicate
      * the current state of tethering.  Each include a list of
      * interface names in that state (may be empty).
@@ -320,10 +321,17 @@
 
     /**
      * @hide
-     * gives a String[] listing all the interfaces currently tethered
-     * (ie, has dhcp support and packets potentially forwarded/NATed)
+     * gives a String[] listing all the interfaces currently in local-only
+     * mode (ie, has DHCPv4+IPv6-ULA support and no packet forwarding)
      */
-    public static final String EXTRA_ACTIVE_TETHER = "activeArray";
+    public static final String EXTRA_ACTIVE_LOCAL_ONLY = "localOnlyArray";
+
+    /**
+     * @hide
+     * gives a String[] listing all the interfaces currently tethered
+     * (ie, has DHCPv4 support and packets potentially forwarded/NATed)
+     */
+    public static final String EXTRA_ACTIVE_TETHER = "tetherArray";
 
     /**
      * @hide