Set min_sdk_version to be part of mainline modules

Modules contributing mainline modules (APK/APEX) should set
min_sdk_version as well as apex_available.

"apex_inherit" is a special alias to represent "the minimum of all
that the apexes require".

For now setting min_sdk_version doesn't change build outputs.
But build-time checks will be added soon.

Bug: 152655956
Test: m
Change-Id: I23cb55a3a17ac242e7f599fe574ca30074b43506
1 file changed