apex: respect filename property for apk-in-apex

android_app_import supports filename: property, which overrides .apk
filename.

Now, apex packaging rule respects it too.
(Previously, apex packaging ignored it)

Bug: 152163837
Test: m  (soong tests amended)
Change-Id: I72e2f1c923f4d01c42a87bf2232a025adca4c918
diff --git a/apex/apex.go b/apex/apex.go
index 04ed269..f0eb1de 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1736,15 +1736,16 @@
 func apexFileForAndroidApp(ctx android.BaseModuleContext, aapp interface {
 	android.Module
 	Privileged() bool
+	InstallApkName() string
 	OutputFile() android.Path
 	JacocoReportClassesFile() android.Path
 	Certificate() java.Certificate
-}, pkgName string) apexFile {
+}) apexFile {
 	appDir := "app"
 	if aapp.Privileged() {
 		appDir = "priv-app"
 	}
-	dirInApex := filepath.Join(appDir, pkgName)
+	dirInApex := filepath.Join(appDir, aapp.InstallApkName())
 	fileToCopy := aapp.OutputFile()
 	af := newApexFile(ctx, fileToCopy, aapp.Name(), dirInApex, app, aapp)
 	af.jacocoReportClassesFile = aapp.JacocoReportClassesFile()
@@ -2003,14 +2004,13 @@
 					ctx.PropertyErrorf("java_libs", "%q of type %q is not supported", depName, ctx.OtherModuleType(child))
 				}
 			case androidAppTag:
-				pkgName := ctx.DeviceConfig().OverridePackageNameFor(depName)
 				if ap, ok := child.(*java.AndroidApp); ok {
-					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap, pkgName))
+					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap))
 					return true // track transitive dependencies
 				} else if ap, ok := child.(*java.AndroidAppImport); ok {
-					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap, pkgName))
+					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap))
 				} else if ap, ok := child.(*java.AndroidTestHelperApp); ok {
-					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap, pkgName))
+					filesInfo = append(filesInfo, apexFileForAndroidApp(ctx, ap))
 				} else {
 					ctx.PropertyErrorf("apps", "%q is not an android_app module", depName)
 				}