Update for the filter message

gistfile1.txt

1. So in order to save a copy of flightSearch in memory, one way to do that is create a copy constructor in FlightSearch.java, just copy all the private member variable, like:
public FlightSearch(FlightSearch flightSearch) {
     this.mOriginAirport = flightSearch.getOriginAirport();
     this.mDestinationAirport = flightSearch.getDestinationAirport();
     this.mFlightSearchMode = flightSearch.getFlightSearchMode();
     this.mBookingClass = ....
     this.mPrefersNonStop = ...
     this.mOutboundDate = ..
     this.mReturnDate = ..
     this.mNumberOfTravelers = ...
     this.segments = ..
}
public FlightSearch() {}
2. So in FlightSearchFormResult.java, in method updateFlightSearchButton()
add:
     if (!mOldFlightSearch.isValid() || mOldFlightSearch.equals(mFlightSearch)) {
            mOldFlightSearch = new FlightSearch(mFlightSearch);
     }
so we can update the old value by copying the value. 
3. Then we can use oldFlightSearch.equals(newFlightSearch) to decide to reset filter.