Add LOCAL_OVERRIDES_PACKAGES support to androidmk.

It is supposed to be translated to overrides.

Test: Manual test
Change-Id: Ice2e7c5f7669ad1e4c3e82000c8dd52d20a49a7a
diff --git a/androidmk/cmd/androidmk/android.go b/androidmk/cmd/androidmk/android.go
index 99b3523..db88685 100644
--- a/androidmk/cmd/androidmk/android.go
+++ b/androidmk/cmd/androidmk/android.go
@@ -144,6 +144,7 @@
 			"LOCAL_AAPT_FLAGS":            "aaptflags",
 			"LOCAL_PACKAGE_SPLITS":        "package_splits",
 			"LOCAL_COMPATIBILITY_SUITE":   "test_suites",
+			"LOCAL_OVERRIDES_PACKAGES":    "overrides",
 
 			"LOCAL_ANNOTATION_PROCESSORS":        "annotation_processors",
 			"LOCAL_ANNOTATION_PROCESSOR_CLASSES": "annotation_processor_classes",