Convert vintf_fragments to vint_fragment_modules

`vintf_fragments` delegates the build actions to run `assemble_vintf` to
make. Convert this to `vintf_fragment_modules` so that `assemble_vintf`
can be run by an action generated by Soong. This change is part of
mk->soong migration.

Test: atest hal_implementation_test
Test: verified that
$PRODUCT_OUT/vendor/etc/vintf/manifest/face-default.xml (built by make)
matches the equivalent face-default.xml file built by soong
Bug: 382295862

Change-Id: If11e7201719be3309a8052aa84f93e777f8464a9