Enable fsanitize unsigned-integer-overflow in GSM soft decoder

Bug: 23110888
Change-Id: I7361eb0253408c6d50a01d67db6f380a39cb2074
diff --git a/media/libstagefright/codecs/gsm/dec/Android.mk b/media/libstagefright/codecs/gsm/dec/Android.mk
index 562d416..fe8c830 100644
--- a/media/libstagefright/codecs/gsm/dec/Android.mk
+++ b/media/libstagefright/codecs/gsm/dec/Android.mk
@@ -11,7 +11,7 @@
 
 LOCAL_CFLAGS += -Werror
 LOCAL_CLANG := true
-LOCAL_SANITIZE := signed-integer-overflow
+LOCAL_SANITIZE := signed-integer-overflow unsigned-integer-overflow
 
 LOCAL_SHARED_LIBRARIES := \
         libstagefright libstagefright_omx libstagefright_foundation libutils liblog