Allow callers of startTethering to choose local-only mode.

This is useful for OEMs that want to use RNDIS or NCM as a
local-only link that is directly connected to some other host.
This can be used to implement USB tethering using NCM, which
currently only supports local-only mode.

Bug: 175090447
Test: TetheringIntegrationTests:EthernetTetheringTest#testLocalOnlyTethering
Change-Id: I0ffaa46e4640e5b235340a15d25909106ceb0c07
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index da15fa8..c45ce83 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -1426,7 +1426,7 @@
                     break;
                 case CMD_INTERFACE_DOWN:
                     transitionTo(mUnavailableState);
-                    mLog.i("Untethered (interface down) and restarting" + mIfaceName);
+                    mLog.i("Untethered (interface down) and restarting " + mIfaceName);
                     mCallback.requestEnableTethering(mInterfaceType, true /* enabled */);
                     break;
                 default: