Use protobuf-codegen default and add mod_stem.rs

* Upgrade to new protobuf-codegen; use its standard
  default output without local change.
* Allow a sourceProvider to have multiple output files.
  For a stem.proto file, output stem.rs and mod_stem.rs.
* New protobuf-codegen option gen_mod_rs always generates
  output file named "mod.rs". To generate multiple .proto
  files into the same output directory, we need to rename
  mod.rs to mod_<stem>.rs.
* Instead of using the gen_mod_rs option and renaming mod.rs
  to mod_<stem>.rs, we generate the same mod_<stem>.rs
  directly with a simple printf command.

Bug: 170256643
Test: atest -c --host --include-subdirs external/crosvm
Change-Id: Ia09e41029099a6de4d35c96dbabd9ba5514c9019

1 files changed, 1 insertions, 1 deletions

diff --git a/rust/bindgen.go b/rust/bindgen.go
index ac33ff7ef..68f219e45 100644
--- a/rust/bindgen.go
+++ b/rust/bindgen.go
@@ -202,7 +202,7 @@ func (b *bindgenDecorator) GenerateSource(ctx ModuleContext, deps PathDeps) andr
 		},
 	})
 
-	b.BaseSourceProvider.OutputFile = outputFile
+	b.BaseSourceProvider.OutputFiles = android.Paths{outputFile}
 	return outputFile
 }