Update documentation for VisitDirectDeps

Calling this function for dependencies that are not android.Module
results in a hard error rather than a soft skip. Update the doc to
reflect this

Bug: 195369546
Test: TH
Change-Id: I18a0938c6536cf20f239cf98c601722aaecd51e6
diff --git a/android/module.go b/android/module.go
index 11f63bd..b6a5bab 100644
--- a/android/module.go
+++ b/android/module.go
@@ -233,8 +233,8 @@
 
 	// VisitDirectDeps calls visit for each direct dependency.  If there are multiple
 	// direct dependencies on the same module visit will be called multiple times on that module
-	// and OtherModuleDependencyTag will return a different tag for each.  It skips any
-	// dependencies that are not an android.Module.
+	// and OtherModuleDependencyTag will return a different tag for each.  It raises an error if any of the
+	// dependencies are not an android.Module.
 	//
 	// The Module passed to the visit function should not be retained outside of the visit
 	// function, it may be invalidated by future mutators.