Check the contents of an SDK snapshot's generated Android.bp

Test: m nothing
Bug: 143678475
Change-Id: I407d83c79d6b1ad8082e560726f0bfa7cacab3f0
diff --git a/sdk/update.go b/sdk/update.go
index 6d7b3ec..e45bd49 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -249,6 +249,7 @@
 		filesToZip:    []android.Path{bp.path},
 		androidBpFile: bp,
 	}
+	s.builderForTests = builder
 
 	// copy exported AIDL files and stub jar files
 	javaLibs := s.javaLibs(ctx)
@@ -350,6 +351,10 @@
 	return outputZipFile
 }
 
+func (s *sdk) GetAndroidBpContentsForTests() string {
+	return s.builderForTests.androidBpFile.content.String()
+}
+
 func buildSharedNativeLibSnapshot(ctx android.ModuleContext, info *nativeLibInfo, builder android.SnapshotBuilder) {
 	// a function for emitting include dirs
 	printExportedDirCopyCommandsForNativeLibs := func(lib archSpecificNativeLibInfo) {