libbase/liblog: 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: If4ff1fbc31e5be3f5611a4713ae4032aba4ee5f2
Change-Id: If4ff1fbc31e5be3f5611a4713ae4032aba4ee5f2
(cherry picked from commit 3851f7e8)