AndroidMkEntries() returns multiple AndroidMkEntries structs

AndroidMkEntries now returns multiple AndroidMkEntires so that a module
can emit multiple Make modules if needed.

Bug: 128708192
Test: m

Change-Id: I56b6f76d22943b80329951c5acb80a1b932441ad
diff --git a/android/androidmk.go b/android/androidmk.go
index 4893bf4..f3c15e4 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -61,7 +61,7 @@
 
 // Allows modules to customize their Android*.mk output.
 type AndroidMkEntriesProvider interface {
-	AndroidMkEntries() AndroidMkEntries
+	AndroidMkEntries() []AndroidMkEntries
 	BaseModuleName() string
 }
 
@@ -510,10 +510,10 @@
 		return nil
 	}
 
-	entries := provider.AndroidMkEntries()
-	entries.fillInEntries(ctx.Config(), ctx.BlueprintFile(mod), mod)
-
-	entries.write(w)
+	for _, entries := range provider.AndroidMkEntries() {
+		entries.fillInEntries(ctx.Config(), ctx.BlueprintFile(mod), mod)
+		entries.write(w)
+	}
 
 	return nil
 }