Soong AAR prebuilt support

Add support for android_library_import modules that take an
aar file.

Bug: 73724997
Test: m checkbuild
Change-Id: I670b56f0a3b7501d9478a6064a04d0cb9c1bb611
diff --git a/java/app.go b/java/app.go
index dc7f848..34f05b7 100644
--- a/java/app.go
+++ b/java/app.go
@@ -34,7 +34,7 @@
 // AndroidManifest.xml merging
 // package splits
 
-type androidAppProperties struct {
+type appProperties struct {
 	// path to a certificate, or the name of a certificate in the default
 	// certificate directory, or blank to use the default product certificate
 	Certificate *string
@@ -71,7 +71,7 @@
 type AndroidApp struct {
 	Module
 
-	appProperties androidAppProperties
+	appProperties appProperties
 
 	aaptSrcJar    android.Path
 	exportPackage android.Path