Make Traceur a platform app

This change makes Traceur a platform app, reverting the priv-app status
granted in aosp/1415071. This is done because Traceur will otherwise
need explicit permission to show a notification with the current tracing
status.

Bug: 209476712
Test: - Checked that Traceur can still take normal and long traces on
        AOSP userdebug and internal user/userdebug.
      - Checked that the Traceur app is now located in /system/app/
        instead of /system/priv-app/.
Change-Id: Ia1f1952dc990204adb18ef514d39e20c03409336
Merged-In: Ia1f1952dc990204adb18ef514d39e20c03409336
2 files changed