Logging and readability improvements

Rearrange the refresh logic:
1) One log entry per refresh rather than (sometimes) 2.
2) Rearrange the logic to try to keep separate concerns separate.
3) Prepare for the next commit in the chain that modifies scheduling
   behavior.

Bug: 222295093
Test: atest services/tests/servicestests/src/com/android/server/timedetector/NetworkTimeUpdateServiceTest.java
Change-Id: I72976e9c7d0e0193c3f3f5e93bfda128defa3145