Fix VintfObjectTest

Removed hard-coded "version"s in assertions. Instead, the test now
parses XML documents and then compare root elements and "type"s.

Plus, the test now checks if report() reports all four
matrices/manifests.

Bug: 317747397
Test: atest VintfObjectTest
Change-Id: I4bb514e9c0bd78214cb3f03e1b12afec8a301915