Add min_sdk_version to aidlCmd for droidstubs

JavaDoc's implementation of `aidlFlags` omits `min_sdk_version`, and
therefore aidl compiler would default it to a default version.

To fix this, pass the min_sdk_version explicitly

Bug: 253122520
Test: TH
Test: go test ./java
Change-Id: Ia8f639174f8361136596d0e7b3286606f84705cd