Various renames following the name change from "Runtime APEX" to "ART APEX".

In particular ANDROID_RUNTIME_ROOT is now ANDROID_ART_ROOT.

Test: Build & boot
Test: art/tools/run-gtests.sh in chroot
Test: art/test/testrunner/testrunner.py --target --64 in chroot
Test: art/tools/run-libcore-tests.sh --mode=device --variant=X64 in chroot
Test: art/tools/run-jdwp-tests.sh --mode=device --variant=X64 in chroot
Test: m test-art-host-gtest
Test: art/test/testrunner/testrunner.py --host --64
Test: art/tools/run-jdwp-tests.sh --mode=host
Bug: 135753770
Change-Id: Ia74da964e54cf396d66e9e12ea56da4e9483662a
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 736b7f3..36c240e 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -468,9 +468,9 @@
   ART_GTEST_TARGET_ANDROID_I18N_ROOT := $(ART_TEST_ANDROID_I18N_ROOT)
 endif
 
-ART_GTEST_TARGET_ANDROID_RUNTIME_ROOT := '/apex/com.android.art'
-ifneq ($(ART_TEST_ANDROID_RUNTIME_ROOT),)
-  ART_GTEST_TARGET_ANDROID_RUNTIME_ROOT := $(ART_TEST_ANDROID_RUNTIME_ROOT)
+ART_GTEST_TARGET_ANDROID_ART_ROOT := '/apex/com.android.art'
+ifneq ($(ART_TEST_ANDROID_ART_ROOT),)
+  ART_GTEST_TARGET_ANDROID_ART_ROOT := $(ART_TEST_ANDROID_ART_ROOT)
 endif
 
 ART_GTEST_TARGET_ANDROID_TZDATA_ROOT := '/apex/com.android.tzdata'
@@ -528,7 +528,7 @@
 	  ($(ADB) shell "$$(PRIVATE_MAYBE_CHROOT_COMMAND) env $(GCOV_ENV) LD_LIBRARY_PATH=$(4) \
 	       ANDROID_ROOT=$(ART_GTEST_TARGET_ANDROID_ROOT) \
 	       ANDROID_I18N_ROOT=$(ART_GTEST_TARGET_ANDROID_I18N_ROOT) \
-	       ANDROID_RUNTIME_ROOT=$(ART_GTEST_TARGET_ANDROID_RUNTIME_ROOT) \
+	       ANDROID_ART_ROOT=$(ART_GTEST_TARGET_ANDROID_ART_ROOT) \
 	       ANDROID_TZDATA_ROOT=$(ART_GTEST_TARGET_ANDROID_TZDATA_ROOT) \
 	       $$(PRIVATE_TARGET_EXE) \
 	     && touch $$(PRIVATE_GTEST_WITNESS)" \
@@ -781,7 +781,7 @@
 ART_TEST_TARGET_GTEST_RULES :=
 ART_GTEST_TARGET_ANDROID_ROOT :=
 ART_GTEST_TARGET_ANDROID_I18N_ROOT :=
-ART_GTEST_TARGET_ANDROID_RUNTIME_ROOT :=
+ART_GTEST_TARGET_ANDROID_ART_ROOT :=
 ART_GTEST_TARGET_ANDROID_TZDATA_ROOT :=
 ART_GTEST_class_linker_test_DEX_DEPS :=
 ART_GTEST_class_table_test_DEX_DEPS :=