Convert vintf_fragments into vintf_fragment module(s)

Convert vintf_fragments into vintf_fragment module(s) so those manifests
can be handled in the same way between KATI defined system image and
Soong defined system image.

Bug: 322089980
Test: aosp_cf_x86_64_phone build succeeded
Change-Id: I389fd0f3bcb372fbd2ff9062b5d99384f08cb115
1 file changed