libcutils: Set min_sdk_version

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.

Bug: 152655956
Test: m
Merged-In: I453c63fe29607ea0312da5465b03c741486fb670
Change-Id: I453c63fe29607ea0312da5465b03c741486fb670
(cherry picked from commit 88f00f2d)