backtrace: 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.

Exempt-From-Owner-Approval: cherry-pick from AOSP

Bug: 152655956
Test: m
Merged-In: I9ff06ca47c8bc2cc5632ffb3494e4fb8eb79d5a3
Change-Id: I9ff06ca47c8bc2cc5632ffb3494e4fb8eb79d5a3
(cherry picked from commit bc62a194)