Add supported variants to module-info

Export the list of variants (host, host_cross, device) a build module
supports to module-info for downstream tools. The values correspond to
the Soong `host_supported`, `host_cross_supported`, and `device_supported`
attribute values.

Bug: 220263783
Test: m out/target/product/vsoc_x86_64/module-info.json
Change-Id: I10ae6ea21791d0d100686dcabecbce543a9adc3f