Remove hard coded gtest/gmock includes/libs.

Tested that checkbuild passes on volantis.

Bug: http://b/16574165
Change-Id: I7bbbd8b4b926115dec2a90ff36dab32b65a35360
diff --git a/Android.mk b/Android.mk
index cc45ffa..cf162b2 100644
--- a/Android.mk
+++ b/Android.mk
@@ -25,7 +25,6 @@
 buffetCommonCIncludes := \
 	$(LOCAL_PATH)/.. \
 	external/cros/system_api \
-	external/gtest/include \
 
 buffetSharedLibraries := \
 	libapmanager-client \
@@ -153,7 +152,6 @@
 LOCAL_CPP_EXTENSION := $(buffetCommonCppExtension)
 LOCAL_CFLAGS := $(buffetCommonCFlags)
 LOCAL_CPPFLAGS := $(buffetCommonCppFlags)
-LOCAL_C_INCLUDES := external/gtest/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)
 LOCAL_SHARED_LIBRARIES := \
 	libbinder \
@@ -184,7 +182,6 @@
 LOCAL_CPPFLAGS := $(buffetCommonCppFlags)
 LOCAL_C_INCLUDES := \
 	$(buffetCommonCIncludes) \
-	external/gmock/include \
 
 LOCAL_SHARED_LIBRARIES := \
 	$(buffetSharedLibraries) \
@@ -192,7 +189,6 @@
 LOCAL_STATIC_LIBRARIES := \
 	libbrillo-test-helpers \
 	libchrome_test_helpers \
-	libgtest \
 	libgmock \
 	libweave-test \
 	weave-daemon-common \