Add build number to apps' version name for non-platform build

If TARGET_BUILD_WITH_APPS_VERSION_NAME is defined, the build system
will add build number to the apps' default version name.

Bug: 28982976
Change-Id: I536f273b557fe7c935cc4ef1052c3297f8029863
diff --git a/core/definitions.mk b/core/definitions.mk
index e2d5de4..b9ef4d5 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1830,6 +1830,10 @@
 
 # Add BUILD_NUMBER to apps default version name if it's unbundled build.
 ifdef TARGET_BUILD_APPS
+TARGET_BUILD_WITH_APPS_VERSION_NAME := true
+endif
+
+ifdef TARGET_BUILD_WITH_APPS_VERSION_NAME
 APPS_DEFAULT_VERSION_NAME := $(PLATFORM_VERSION)-$(BUILD_NUMBER_FROM_FILE)
 else
 APPS_DEFAULT_VERSION_NAME := $(PLATFORM_VERSION)