Android LauncherがonCreateを2回開く理由

 com.android.server.am.ActivityStack
    /**
     * Make sure the given activity matches the current configuration.  Returns
     * false if the activity had to be destroyed.  Returns true if the
     * configuration is the same, or the activity will remain running as-is
     * for whatever reason.  Ensures the HistoryRecord is updated with the
     * correct configuration and all other bookkeeping is handled.
     */
    final boolean ensureActivityConfigurationLocked(ActivityRecord r,
            int globalChanges) {
        ...
        if ((changes&(~r.info.configChanges)) != 0) {
            // Aha, the activity isn't handling the change, so DIE DIE DIE.
            r.configChangeFlags |= changes;
            r.startFreezingScreenLocked(r.app, globalChanges);
            if (r.app == null || r.app.thread == null) {
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is destroying non-running " + r);
                destroyActivityLocked(r, true);
            } else if (r.state == ActivityState.PAUSING) {
                // A little annoying: we are waiting for this activity to
                // finish pausing.  Let's not do anything now, but just
                // flag that it needs to be restarted when done pausing.
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is skipping already pausing " + r);
                r.configDestroy = true;
                return true;
            } else if (r.state == ActivityState.RESUMED) {
                // Try to optimize this case: the configuration is changing
                // and we need to restart the top, resumed activity.
                // Instead of doing the normal handshaking, just say
                // "restart!".
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is restarting resumed " + r);
                
                relaunchActivityLocked(r, r.configChangeFlags, true);
                r.configChangeFlags = 0;
            } else {
                if (DEBUG_SWITCH || DEBUG_CONFIGURATION) Slog.v(TAG,
                        "Switch is restarting non-resumed " + r);
                relaunchActivityLocked(r, r.configChangeFlags, false);
                r.configChangeFlags = 0;
            }
            
            // All done...  tell the caller we weren't able to keep this
            // activity around.
            return false;
        }
        ...
       }

注意上記コードの13行目と41行目
Why:
システムが起動すると、利用可能なモバイルネットワークを検索するとconfig changes:mcc|mncがトリガーされます.
「mcc」The IMSI mobile country code(MCC)has changed-that is,a SIM hasbeen detected and updated the MCC.モバイル国番号は、3桁の数字で構成されており、それぞれの国に独自のMCCがあり、携帯電話ユーザーの所属国を識別することができる.「mnc」The IMSI mobile network code(MNC) has changed — that is, a SIM hasbeen detected and updated the MNC.携帯電話のユーザーを区別するためのサービス業者.
HowTo: