Pass --api-surface to Metalava

Uses the `api_surface` property and passes it down to Metalava. It will
use it to select the appropriate `<api-surface>` configuration in
`build/soong/java/metalava/main-config.xml`.

Bug: 391554590
Test: m checkapi
Change-Id: I5ec4e121239e6ecbc4dc1b2958a164f93bb8b437