Add privileged app support in Soong

Allow apps to specify that they should be installed in priv-app,
and export the value to Make which normally handles installation.

Test: m checkbuild
Change-Id: I79a05e7bb6ec0df5c31429e2f4592c6fd57dab70
diff --git a/java/androidmk.go b/java/androidmk.go
index 32ee7ac..1115114 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -177,6 +177,9 @@
 
 				fmt.Fprintln(w, "LOCAL_FULL_MANIFEST_FILE :=", app.manifestPath.String())
 
+				if Bool(app.appProperties.Privileged) {
+					fmt.Fprintln(w, "LOCAL_PRIVILEGED_MODULE := true")
+				}
 			},
 		},
 	}