Fix build breakage due to incorrect bcc_compat RS_TRIPLE.

Bug: 17333374
Change-Id: I13582ce0cde86f7b3728aa4f45a5197438d65a2d
(cherry picked from commit 52626d2a7b4767905e8a369ddc8316c1290ad156)
diff --git a/core/clang/TARGET_arm64.mk b/core/clang/TARGET_arm64.mk
index 0264321..6f9e540 100644
--- a/core/clang/TARGET_arm64.mk
+++ b/core/clang/TARGET_arm64.mk
@@ -52,3 +52,4 @@
 
 RS_TRIPLE := aarch64-linux-android
 RS_TRIPLE_CFLAGS :=
+RS_COMPAT_TRIPLE := aarch64-linux-android