Reduce unnecessary string operation for input info

WindowState#getName always creates a new string that
concatenates hashcode and layout parameter title.
If the title is not changed, it is unnecessary to update
every time for all windows when updating input info.

Bug: 442747045
Flag: EXEMPT Only relevant for logging
Test: Show a dialog. Change the title by Dialog#setTitle
      (which calls WindowManager.LayoutParams#setTitle).
      The new name should be shown in "adb shell dumpsys input".
Change-Id: I2b0c92aea1b73979e6e87198c6b981c02fe72e26