Add ART_DEXPREOPT_BOOT_JAR_DIR.

Replaces DEXPREOPT_BOOT_JAR_DIR which was removed here:
https://android-review.googlesource.com/q/topic:%22dexpreopt_bootjars%22+(status:open%20OR%20status:merged)

Test: art/tools/run-gtests.sh
Change-Id: Ic09ccc17fa689fcb23383e7abda4b9ac24ec2ff1
diff --git a/build/Android.common.mk b/build/Android.common.mk
index d024e77..e96e3ed 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -19,6 +19,7 @@
 
 ART_TARGET_SUPPORTED_ARCH := arm arm64 mips mips64 x86 x86_64
 ART_HOST_SUPPORTED_ARCH := x86 x86_64
+ART_DEXPREOPT_BOOT_JAR_DIR := system/framework
 
 ifneq ($(HOST_OS),darwin)
   ART_HOST_SUPPORTED_ARCH := x86 x86_64