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/apex/prebuilt.go b/apex/prebuilt.go
index db3b5ef..ba5a466 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -181,8 +181,8 @@
 	// TODO(b/143192278): Add compat symlinks for prebuilt_apex
 }
 
-func (p *Prebuilt) AndroidMkEntries() android.AndroidMkEntries {
-	return android.AndroidMkEntries{
+func (p *Prebuilt) AndroidMkEntries() []android.AndroidMkEntries {
+	return []android.AndroidMkEntries{android.AndroidMkEntries{
 		Class:      "ETC",
 		OutputFile: android.OptionalPathForPath(p.inputApex),
 		Include:    "$(BUILD_PREBUILT)",
@@ -194,5 +194,5 @@
 				entries.AddStrings("LOCAL_OVERRIDES_MODULES", p.properties.Overrides...)
 			},
 		},
-	}
+	}}
 }