Add TODO bug number to stop hardcoding 'droid'

Test: N/A
Signed-off-by: Jingwen Chen <jingwen@google.com>
Change-Id: I0d60cc4254b3a358085d89e443bd3bfc33b68ed3
diff --git a/ui/build/bazel.go b/ui/build/bazel.go
index 978553d..4b9fdc7 100644
--- a/ui/build/bazel.go
+++ b/ui/build/bazel.go
@@ -23,6 +23,8 @@
 
 func runBazel(ctx Context, config Config) {
 	// "droid" is the default ninja target.
+	// TODO(b/160568333): stop hardcoding 'droid' to support building any
+	// Ninja target.
 	outputGroups := "droid"
 	if len(config.ninjaArgs) > 0 {
 		// At this stage, the residue slice of args passed to ninja