Assign ownership to the AnrTimer files in the java source, java unit
test, and jni directories.

Bug: 282428924

Test: none - OWNERS only

Change-Id: I208296bc0cf8369d59ef51c620f50939f843173d

This will simplify reviews as multiple folks develop on this file
but are not yet owners.

Test: NA
Bug: 264896530
Change-Id: I07c4543c947c3e240416f26a8a3cdbe6c728dfd7