Enable codecs on bot linux-bfcache-rel

This bot runs WPT so needs H264 enabled as well.

BUG=chromium:840659,chromium:1103214

Change-Id: I9962b9f7618c9db663a8a4f26b539801c74b8c4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2362795Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Harald Alvestrand <hta@chromium.org>
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804459}

tools/mb/mb_config.pyl

@@ -492,7 +492,7 @@
       'fuchsia-arm64-cast': 'release_bot_fuchsia_arm64_cast',
       'fuchsia-x64-cast': 'release_bot_fuchsia_cast',
       'fuchsia-x64-dbg': 'debug_bot_fuchsia_compile_only',
-      'linux-bfcache-rel': 'release_bot',
+      'linux-bfcache-rel': 'release_bot_blink',
       'linux-gcc-rel': 'release_bot_x86_minimal_symbols_no_clang_cxx11',
       'linux-ozone-rel': 'ozone_linux_release_bot',
       'linux-trusty-rel': 'gpu_tests_release_bot',
@@ -895,7 +895,7 @@
       'linux-autofill-assistant': 'autofill_assistant_release_trybot',
       'linux-blink-heap-concurrent-marking-tsan-rel': 'release_trybot_tsan',
       'linux-blink-heap-verification-try': 'release_trybot_enable_blink_heap_verification',
-      'linux-bfcache-rel': 'release_bot',
+      'linux-bfcache-rel': 'release_bot_blink',
       'linux-clang-tidy-dbg': 'debug_bot',
       'linux-clang-tidy-rel': 'release_trybot',
       'linux-dcheck-off-rel': 'release_trybot_dcheck_off',