Externalize premium/reserved list tests

Remove the GoogleInternal designator on the premium/reserved list tests, move
the lists themselves under the config/files directory, and fix all of the
surrounding infrastructure.

The lists do not get exported.  Only the "example.txt" list does, allowing the
test to function on the open source build.

TESTED:
  Verified that the gradle build works and that only the example.txt file is exported.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=229940659

java/google/registry/config/files/premium/BUILD

@@ -0,0 +1,10 @@
+licenses(["notice"])  # Apache 2.0
+
+package(
+    default_visibility = ["//java/google/registry:registry_project"],
+)
+
+filegroup(
+    name = "all_lists",
+    srcs = glob(["*.txt"]),
+)

java/google/registry/config/files/premium/example.txt

@@ -0,0 +1,7 @@
+# Example of a reserved list file.  This is simply a CSV file with two
+# columns: sub-domain name and price (specified as currency type and value).
+#
+# These are manipulated using the "nomulus" tool
+# {create,update,delete,list}_premium_list commands.
+foo,USD 100 # comment after the item
+bar,JPY 14