One updateSummary method called by all VPN prefs

Having multiple methods means inevitably when new features are added to
the preferences, the right calls aren't made so information on the
screen lags between updates.

Bug: 28257641
Change-Id: I336aeefd5941ccf808dc9070427209a7d2530032
(cherry picked from commit 903843e6f9)

src/com/android/settings/vpn2/LegacyVpnPreference.java

@@ -31,9 +31,6 @@ import static com.android.internal.net.LegacyVpnInfo.STATE_CONNECTED;
 public class LegacyVpnPreference extends ManageablePreference {
     private VpnProfile mProfile;
 
-    /** One of the STATE_* fields from LegacyVpnInfo, or STATE_NONE */
-    private int mState = STATE_NONE;
-
     LegacyVpnPreference(Context context) {
         super(context, null /* attrs */);
     }
@@ -44,16 +41,6 @@ public class LegacyVpnPreference extends ManageablePreference {
 
     public void setProfile(VpnProfile profile) {
         mProfile = profile;
-        update();
-    }
-
-    public void setState(int state) {
-        mState = state;
-        update();
-    }
-
-    private void update() {
-        setSummary(getSummaryString(mState));
         if (mProfile != null) {
             setIcon(R.mipmap.ic_launcher_settings);
             setTitle(mProfile.name);
@@ -93,5 +80,4 @@ public class LegacyVpnPreference extends ManageablePreference {
         }
         super.onClick(v);
     }
-
-}
+}