Change the triplet to aarch64-linux-android for aarch64-gcc.

Change-Id: I0d8803b45b5085379e01d616a1056201453bda9f

configure

diff --git a/configure b/configure
index f2638a7..8ae5bd6 100755
--- a/configure
+++ b/configure
@@ -2017,7 +2017,7 @@
   arm-newlib-elf)
     BUILD_ANDROID_GCC=no
     ;;
-  aarch64-unknown-linux-androideabi)
+  aarch64-unknown-linux-android)
     BUILD_ANDROID_GCC=yes
     GDB_TARGET=aarch64-elf-linux
     ;;