Merge VtsFiemapWriterTest into fiemap_writer_test

Delete AndroidTest.xml for VtsFiemapWriterTest and use auto-generated
test config for fiemap_writer_test.

Also add fiemap_writer_test to vts-core and device-tests.

Also require_root for fiemap_writer_test.

Test: atest fiemap_writer_test
Fixes: 144300653
Change-Id: Ifc3808ea56331809b58f0c02de2caac250d78352