AAPT2: Specify the output APK in log messages

Extend the context wrapper to allow it to also know the current artifact
that is being generated and to use that as a source for diagnostics
messages.

Test: ran unit tests
Test: manually ran optimize to split and APK and verified log messages

Change-Id: I1d66dacb38db58d57d2fffaa19f5fdaff9f908df
diff --git a/tools/aapt2/optimize/MultiApkGenerator.h b/tools/aapt2/optimize/MultiApkGenerator.h
index e6546ee..c9b4be8 100644
--- a/tools/aapt2/optimize/MultiApkGenerator.h
+++ b/tools/aapt2/optimize/MultiApkGenerator.h
@@ -47,7 +47,7 @@
   virtual std::unique_ptr<ResourceTable> FilterTable(
       const configuration::Artifact& artifact,
       const configuration::PostProcessingConfiguration& config, const ResourceTable& old_table,
-      FilterChain* chain);
+      IAaptContext* context, FilterChain* chain);
 
  private:
   IDiagnostics* GetDiagnostics() {