updatable-media: 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.

updatable-media is a member of com.android.media.

Bug: 152655956
Test: m
Change-Id: I82cecd20888189657693cb9f406c831c6aa42905