The certificate module is handled the same in Soong between android apps
and apexes, so share the bp2build code as well.
There are a few changes in this CL:
- If override_apex.certificate is unset, the generated apex also unsets
it. This prevents the generated apex from using the base apex's
certificate, which is most likely incorrect (e.g. google variant using
the cert for the aosp variant). Instead, rely on the default
certificate handling in the macro.
- If the certificate prop is a string, then it gets generated into
certificate_name in order to disambiguate. This behavior is identical
to android_app.
Test: added various unit tests.
Bug: 249089160
Fixes: 249089160
Change-Id: I99e18964ff546429a985d0f64dc21e2c69d35d9d
bea58093b4