Fix the Trust Tokens key commitment fuzzer

There's some global state that the key commitment fuzzer needs
initialized, or else it (evidently) crashes. So far, this seems to
include ICU and the command line. This change adds a dependency on
//net:net_fuzzer_test_support in order to initialize net-relevant global
state, including those two.

R=svaldez

Fixed: 1071130, 1071084, 1071157
Change-Id: If92e8a9e3a7905e0966950cc45576fd9549adca0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2151105Reviewed-by: Steven Valdez <svaldez@chromium.org>
Commit-Queue: Steven Valdez <svaldez@chromium.org>
Auto-Submit: David Van Cleve <davidvc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759400}

services/network/trust_tokens/BUILD.gn

@@ -165,6 +165,7 @@ fuzzer_test("trust_token_key_commitment_parser_fuzzer") {
   deps = [
     ":trust_tokens",
     "//base",
+    "//net:net_fuzzer_test_support",
     "//services/network/public/mojom",
   ]
   dict = "test/trust_token_key_commitment_parser_fuzzer.dict"