Add source file provider for genrule/srcs, python libraries and rust libraries.

Ignore-AOSP-First: CPing test_spec rule to udc-mainline-prod to support migration of test targets. Cherry pick of:aosp/2786121

Change-Id: I2d7d4684a10c15aeecc27b8db800ab27a807d2e2
Merged-In: I2d7d4684a10c15aeecc27b8db800ab27a807d2e2
diff --git a/python/python.go b/python/python.go
index 1a12973..353cc65 100644
--- a/python/python.go
+++ b/python/python.go
@@ -404,6 +404,7 @@
 // GenerateAndroidBuildActions performs build actions common to all Python modules
 func (p *PythonLibraryModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	expandedSrcs := android.PathsForModuleSrcExcludes(ctx, p.properties.Srcs, p.properties.Exclude_srcs)
+	ctx.SetProvider(blueprint.SrcsFileProviderKey, blueprint.SrcsFileProviderData{SrcPaths: expandedSrcs.Strings()})
 
 	// expand data files from "data" property.
 	expandedData := android.PathsForModuleSrc(ctx, p.properties.Data)