Add some more properties to the bp2build APEX converter (second try)

In particular:

- AndroidManifest
- file_contexts
- key
- certificate
- min_sdk_version
- updatable
- installable
- native_shared_libs
- binaries

Test: Updated unit test

Change-Id: I1c6e8c4b6b24ce487f64e5d37bd594dbb000fe6f
diff --git a/apex/key.go b/apex/key.go
index 8b33b59..4bd0dc4 100644
--- a/apex/key.go
+++ b/apex/key.go
@@ -37,6 +37,7 @@
 
 type apexKey struct {
 	android.ModuleBase
+	android.BazelModuleBase
 
 	properties apexKeyProperties
 
@@ -61,6 +62,7 @@
 	module := &apexKey{}
 	module.AddProperties(&module.properties)
 	android.InitAndroidArchModule(module, android.HostAndDeviceDefault, android.MultilibCommon)
+	android.InitBazelModule(module)
 	return module
 }