Rename some build variables and targets for the ART APEX.

Test: m
Bug: 135753770
Change-Id: I66273981013710500e5e57c0a3c40a5fdc61e3d0
diff --git a/build/Android.common_path.mk b/build/Android.common_path.mk
index 4251a2e..9c8a45d 100644
--- a/build/Android.common_path.mk
+++ b/build/Android.common_path.mk
@@ -147,12 +147,12 @@
 ART_HOST_EXECUTABLES += $(foreach name,$(ART_CORE_DEBUGGABLE_EXECUTABLES),$(name)d-host)
 endif
 
-# Release Runtime APEX, included by default in "user" builds.
-RELEASE_RUNTIME_APEX := com.android.art.release
-# Debug Runtime APEX, included by default in "userdebug" and "eng"
+# Release ART APEX, included by default in "user" builds.
+RELEASE_ART_APEX := com.android.art.release
+# Debug ART APEX, included by default in "userdebug" and "eng"
 # builds and used in ART device benchmarking.
-DEBUG_RUNTIME_APEX := com.android.art.debug
-# Testing Runtime APEX, used in ART device testing.
-TESTING_RUNTIME_APEX := com.android.art.testing
+DEBUG_ART_APEX := com.android.art.debug
+# Testing ART APEX, used in ART device testing.
+TESTING_ART_APEX := com.android.art.testing
 
 endif # ART_ANDROID_COMMON_PATH_MK