Allow to build host gtest libraries in unbundled build.

You need to include external/libcxx and external/libcxxabi in the
unbundled branche's repo manifest, though.

Change-Id: I778f36ef941beb932ef28c02188b8c855435b051
diff --git a/src/Android.mk b/src/Android.mk
index adcb6d5..d9ba471 100644
--- a/src/Android.mk
+++ b/src/Android.mk
@@ -75,8 +75,6 @@
 
 include $(BUILD_STATIC_LIBRARY)
 
-# Don't build for unbundled branches
-ifeq (,$(TARGET_BUILD_APPS))
 #######################################################################
 # libc++
 
@@ -115,6 +113,8 @@
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 #######################################################################
+# Don't build for unbundled branches
+ifeq (,$(TARGET_BUILD_APPS))
 # gtest lib target
 
 include $(CLEAR_VARS)