Add mb configuration for Chromium Win 10 GCE Tests (Win 10 Build)

Also rename Chromium Win 10 GCE Tests to Chromium Win 10 GCE Tests (Win 7 Build).

Bug: 738255
Change-Id: I6fd66ad6ed7a141bbcd252e61228e93d2656acb2
Reviewed-on: https://chromium-review.googlesource.com/570984Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: smut <smut@google.com>
Cr-Commit-Position: refs/heads/master@{#486591}

tools/mb/mb_config.pyl

@@ -120,7 +120,8 @@
       'Chromium Mac 10.9 Goma Canary (dbg)': 'debug_bot',
       'Chromium Mac 10.9 Goma Canary (dbg)(clobber)': 'debug_bot',
       'Chromium Mac Goma Canary LocalOutputCache': 'release_bot',
-      'Chromium Win 10 GCE Tests': 'release_bot_x86_minimal_symbols',
+      'Chromium Win 10 GCE Tests (Win 7 Build)': 'release_bot_x86_minimal_symbols',
+      'Chromium Win 10 GCE Tests (Win 10 Build)': 'release_bot_x86_minimal_symbols',
       'Chromium Win PGO Builder': {
         '1': 'official_optimize_chrome_pgo_phase_1_x86',
         '2': 'official_optimize_chrome_pgo_phase_2_x86',