VNDK snapshot may provide LLNDK stub libraries

VNDK snapshots newer than v30 have LLNDK stub libraries. In that
case, the vendor variant for the BOARD_VNDK_VERSION must not be
generated from the LLNDK modules. They are already provided by the
VNDK snapshots.
Generate the vendor variant of the BOARD_VNDK_VERSION only if
BOARD_VNDK_VERSION has an integer value less than or equal to 30.

Bug: 187963715
Bug: 181815415
Test: m nothing
Change-Id: I31e90f4d7e7678c45558f6bf987f5582a4c34f78

cc/image.go

@@ -430,6 +430,16 @@ func MutateImage(mctx android.BaseModuleContext, m ImageMutatableModule) {
 	recoverySnapshotVersion := mctx.DeviceConfig().RecoverySnapshotVersion()
 	usingRecoverySnapshot := recoverySnapshotVersion != "current" &&
 		recoverySnapshotVersion != ""
+	needVndkVersionVendorVariantForLlndk := false
+	if boardVndkVersion != "" {
+		boardVndkApiLevel, err := android.ApiLevelFromUser(mctx, boardVndkVersion)
+		if err == nil && !boardVndkApiLevel.IsPreview() {
+			// VNDK snapshot newer than v30 has LLNDK stub libraries.
+			// Only the VNDK version less than or equal to v30 requires generating the vendor
+			// variant of the VNDK version from the source tree.
+			needVndkVersionVendorVariantForLlndk = boardVndkApiLevel.LessThanOrEqualTo(android.ApiLevelOrPanic(mctx, "30"))
+		}
+	}
 	if boardVndkVersion == "current" {
 		boardVndkVersion = platformVndkVersion
 	}
@@ -446,7 +456,9 @@ func MutateImage(mctx android.BaseModuleContext, m ImageMutatableModule) {
 			vendorVariants = append(vendorVariants, platformVndkVersion)
 			productVariants = append(productVariants, platformVndkVersion)
 		}
-		if boardVndkVersion != "" {
+		// Generate vendor variants for boardVndkVersion only if the VNDK snapshot does not
+		// provide the LLNDK stub libraries.
+		if needVndkVersionVendorVariantForLlndk {
 			vendorVariants = append(vendorVariants, boardVndkVersion)
 		}
 		if productVndkVersion != "" {