Tweak back gesture logging output

- Fix issue where isTrackpadMultiFingerSwipe is swapped and incorrectly
  logged as mAllowGesture
- Add some missing states that might affect allow state
- Adding user-readable timestamp to make it easier to cross reference
  with logcat

Bug: 281681250
Test: adb shell dumpsys activity service SystemUIService

Change-Id: Id1fc5bc280c516e3a68d6a9a9734b8b3ac09ad00
Merged-In: Id1fc5bc280c516e3a68d6a9a9734b8b3ac09ad00