Add manifest kernel FCM version

Add target-level attribute to manifest.kernel. A device manifest
can specify this attribute to specify the kernel requirements which
FCM version it conforms to.

This CL adds parsing code for the target-level attribute.

Test: libvintf_test
Bug: 139309488

Change-Id: Ibd29e0778432d046e06345d8c6e22656773819c2
4 files changed