Condition VNDK check on TARGET_BUILD_APPS

Bug: 113560265
Test: (with the topic)
Test: mv prebuilts/vndk/v28 v28
Test: make TARGET_PRODUCT=aosp_arm TARGET_BUILD_APPS=Launcher3 TARGET_BUILD_VARIANT=userdebug
      --> build pass
Test: lunch aosp_arm-userdebug
      --> error: VNDK version 28 not found
Test: mv v28 prebuilts/vndk/v28
Test: lunch aosp_arm-userdebug
      --> no error
Change-Id: Ifb553a5ee4cec8b3f3b79aebdf824d64571fa817
diff --git a/core/envsetup.mk b/core/envsetup.mk
index 8ffbc19..66d7c1b 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -446,9 +446,11 @@
   TARGET_VENDOR_TEST_SUFFIX :=
 endif
 
+ifeq (,$(TARGET_BUILD_APPS))
 ifdef PRODUCT_EXTRA_VNDK_VERSIONS
   $(foreach v,$(PRODUCT_EXTRA_VNDK_VERSIONS),$(call check_vndk_version,$(v)))
 endif
+endif
 
 # Ensure that BOARD_SYSTEMSDK_VERSIONS are all within PLATFORM_SYSTEMSDK_VERSIONS
 _unsupported_systemsdk_versions := $(filter-out $(PLATFORM_SYSTEMSDK_VERSIONS),$(BOARD_SYSTEMSDK_VERSIONS))