Use string_view instead of string for json.

This supports char* and ::std::string.

Change-Id: I2b9aea9feacbfc16baf01f7750be52b44fc6fbe4
diff --git a/aos/BUILD b/aos/BUILD
index c73336e..0631e66 100644
--- a/aos/BUILD
+++ b/aos/BUILD
@@ -433,6 +433,7 @@
         ":flatbuffer_utils",
         "//aos/logging",
         "@com_github_google_flatbuffers//:flatbuffers",
+        "@com_google_absl//absl/strings",
     ],
 )