apex.use_vndk_as_stable can't be used with min_sdk_version

For vendor apexes, use_vndk_as_stable: true means the apex is tied with
the current VNDK version while min_sdk_version: N means the apex should
work with N+ VNDK versions. Setting both properties together doesn't
make sense.

Bug: 274396342
Test: m nothing (soong tests)
Change-Id: I00dcac43f95ce6a90b3f3273ae4611a300ea5028