Added the class name of activity being autofilled on (most) autofill metrics.

Test: atest CtsAutoFillServiceTestCases # to make sure it didn't break anything
Test: manually run some test and watched
      'adb shell logcat -b events | grep sysui'

Fixes: 80151641

Change-Id: I5b83e6ceb549a641d10c39bbfd4f24d0a43d1a23
(cherry picked from commit 212b1614)