Add PhonyOutput to BuildParams

Now ctx.Build() can be used to create phony rules which have commands.

Bug: 396145326
Test: manual, TH
Change-Id: I60ab42b5478a12d7c5e6ea7a5b772c23fa49692d
diff --git a/android/module_context.go b/android/module_context.go
index 1851e7c..089e184 100644
--- a/android/module_context.go
+++ b/android/module_context.go
@@ -81,6 +81,8 @@
 	Default bool
 	// Args is a key value mapping for replacements of variables within the Rule
 	Args map[string]string
+	// PhonyOutput marks this build as `phony_output = true`
+	PhonyOutput bool
 }
 
 type ModuleBuildParams BuildParams
@@ -369,6 +371,7 @@
 		Validations:     params.Validations.Strings(),
 		Args:            params.Args,
 		Default:         params.Default,
+		PhonyOutput:     params.PhonyOutput,
 	}
 
 	if params.Depfile != nil {