Don't update state after stop bluetooth tethering

After using ConnectivityManager.stopTethering(), TetheringSettings may
update state before PanService set mTetherOn to false. This makes the
toggle button checked again and user need click it twice to disable it.

Bug: 111578971
Test: on/off bluetooth tethering from settings UI
Change-Id: I6873d762d2a290080d844b7a44e54f4bd532347e

src/com/android/settings/TetherSettings.java

@@ -423,9 +423,6 @@ public class TetherSettings extends RestrictedSettingsFragment
                 startTethering(TETHERING_BLUETOOTH);
             } else {
                 mCm.stopTethering(TETHERING_BLUETOOTH);
-                // No ACTION_TETHER_STATE_CHANGED is fired or bluetooth unless a device is
-                // connected. Need to update state manually.
-                updateState();
             }
         }