Remove obsolete AnrTimer Java code

This removes obsolete AnrTimer java code.  The aconfig flag is unused
but it is retained for use in the next CL.  The unit test is updated.

Test: atest
 * FrameworksServicesTests:com.android.server.am
 * FrameworksServicesTests:com.android.server.utils
 * FrameworksMockingServicesTests:com.android.server.am

Bug: 282428924

Change-Id: I131f329f2651a4a316bc4de8fa2e905c267b10f3
2 files changed