Re-organize dvr_tracking headers

1/ dvr_tracking_types.h is public header, include it in dvr_api.h
2/ dvr_tracking.h is private header, only include it in dvr_api.cpp
3/ Forward declare DvrTrackingXXX opaque handles and callback
   signatures in dvr_api.h

Bug: 78169521
Test: Build system
Change-Id: I5583dd7ad6a403fd4f2429770f30c1ba696e8430
2 files changed