Replaces logTrace logging in TouchExplorer with Slog

For ease of use, the old logTrace logs will be replaced with Slog logging.
This comes from a desire for more readily-available information in the debugging process.

Test: adb shell setprop log.tag.TouchExplorer DEBUG | adb logcat --buffer=system | grep -e "TouchExplorer"
Bug: 374930391
Flag: EXEMPT only changes debug logging
Change-Id: I40a9814ae9c38a19f7132f22cece4ea38d162f3b