Change current flatbuffer library name to represent version. (#1366)

tensorflow/workspace.bzl

-load("//third_party/flatbuffers:workspace.bzl", flatbuffers = "repo")
+load("//third_party/flatbuffers_v_1_12:workspace.bzl", flatbuffers = "repo")
 load("//third_party/kissfft:workspace.bzl", kissfft = "repo")
 load("//third_party/ruy:workspace.bzl", ruy = "repo")
 load("//third_party:repo.bzl", "tf_http_archive")

third_party/flatbuffers/workspace.bzl → third_party/flatbuffers_v_1_12/workspace.bzl

@@ -11,9 +11,9 @@ def repo():
             "https://storage.googleapis.com/mirror.tensorflow.org/github.com/google/flatbuffers/archive/v1.12.0.tar.gz",
             "https://github.com/google/flatbuffers/archive/v1.12.0.tar.gz",
         ],
-        build_file = "//third_party/flatbuffers:BUILD.bazel",
-        system_build_file = "//third_party/flatbuffers:BUILD.system",
+        build_file = "//third_party/flatbuffers_v_1_12:BUILD.bazel",
+        system_build_file = "//third_party/flatbuffers_v_1_12:BUILD.system",
         link_files = {
-            "//third_party/flatbuffers:build_defs.bzl": "build_defs.bzl",
+            "//third_party/flatbuffers_v_1_12:build_defs.bzl": "build_defs.bzl",
         },
     )