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.

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

This is one of two parts: covers mainline-related files.

Bug: 152655956
Test: m
Change-Id: I558b2d717d6cbae920db008d1b0f3ed61958937b