Add level attribute to <kernel> in compatibility matrix xsd

Test: builds
Bug: 149929588
Change-Id: Ic8588c380803cf34f2bcd5ded00ffc9779e770d1
(cherry picked from commit fa5ce752dcf7e863ec11dd2e182042653f8af33b)
Merged-In: Ic8588c380803cf34f2bcd5ded00ffc9779e770d1
2 files changed