[soong] new field in Android.bp to request APK signing V4

If "v4_signature: true" is set, the v4 signature file,
named [outputApkFile].idsig
will be generated along side the outputApkFile.

Test: m nothing
Test: atest PackageManagerShellCommandIncrementalTest
BUG: 149354175
Change-Id: Ie84725a15406f96f65042ea9909460e4eb34d57f
Merged-In: Ie84725a15406f96f65042ea9909460e4eb34d57f
diff --git a/java/app.go b/java/app.go
index fc3ce97..e278b9c 100755
--- a/java/app.go
+++ b/java/app.go
@@ -514,14 +514,28 @@
 
 	// Build a final signed app package.
 	packageFile := android.PathForModuleOut(ctx, a.installApkName+".apk")
-	CreateAndSignAppPackage(ctx, packageFile, a.exportPackage, jniJarFile, dexJarFile, certificates, apkDeps)
+	v4SigningRequested := Bool(a.Module.deviceProperties.V4_signature)
+	var v4SignatureFile android.WritablePath = nil
+	if v4SigningRequested {
+		v4SignatureFile = android.PathForModuleOut(ctx, a.installApkName+".apk.idsig")
+	}
+	CreateAndSignAppPackage(ctx, packageFile, a.exportPackage, jniJarFile, dexJarFile, certificates, apkDeps, v4SignatureFile)
 	a.outputFile = packageFile
+	if v4SigningRequested {
+		a.extraOutputFiles = append(a.extraOutputFiles, v4SignatureFile)
+	}
 
 	for _, split := range a.aapt.splits {
 		// Sign the split APKs
 		packageFile := android.PathForModuleOut(ctx, a.installApkName+"_"+split.suffix+".apk")
-		CreateAndSignAppPackage(ctx, packageFile, split.path, nil, nil, certificates, apkDeps)
+		if v4SigningRequested {
+			v4SignatureFile = android.PathForModuleOut(ctx, a.installApkName+"_"+split.suffix+".apk.idsig")
+		}
+		CreateAndSignAppPackage(ctx, packageFile, split.path, nil, nil, certificates, apkDeps, v4SignatureFile)
 		a.extraOutputFiles = append(a.extraOutputFiles, packageFile)
+		if v4SigningRequested {
+			a.extraOutputFiles = append(a.extraOutputFiles, v4SignatureFile)
+		}
 	}
 
 	// Build an app bundle.
@@ -1122,7 +1136,7 @@
 		}
 		a.certificate = certificates[0]
 		signed := android.PathForModuleOut(ctx, "signed", ctx.ModuleName()+".apk")
-		SignAppPackage(ctx, signed, dexOutput, certificates)
+		SignAppPackage(ctx, signed, dexOutput, certificates, nil)
 		a.outputFile = signed
 	} else {
 		alignedApk := android.PathForModuleOut(ctx, "zip-aligned", ctx.ModuleName()+".apk")
@@ -1327,7 +1341,7 @@
 	_, certificates := collectAppDeps(ctx, false, false)
 	certificates = processMainCert(r.ModuleBase, String(r.properties.Certificate), certificates, ctx)
 	signed := android.PathForModuleOut(ctx, "signed", r.Name()+".apk")
-	SignAppPackage(ctx, signed, r.aapt.exportPackage, certificates)
+	SignAppPackage(ctx, signed, r.aapt.exportPackage, certificates, nil)
 	r.certificate = certificates[0]
 
 	r.outputFile = signed