Set module min_sdk_version to 28

The modules are not actually compatible with 28, but this is necessary
as tooling does not support "Q" as a version in the APK.

This will need to be changed to the new version number as soon as it is
available.

Test: m
Change-Id: I1d88f80c293b4667244d219a6989dd11be90f12a
6 files changed