Added EdgeTPU vendor service into P21.

The original edgetpu_service is now split into two, where the
original one stays under /system_ext/ and the new one,
edgetpu_vendor_service, now locates under /vendor/.

This change updates files including device.mk accordingly to
ensure these services are setup properly on P21.

Bug: 185432427
Test: Oriole + GCA
Change-Id: I5b0eff64f2f044a56bc14cf5e1d92ec3463560a9
3 files changed