Deflake TLSDeprecationConfigTest.NoProto

This is a follow up to crrev.com/c/2141099

The test is still flaky because of its dependency on a singleton class.

crrev.com/c/2141099 cleared the state after running each test to make
sure not other tests are affected.

This CL clears the states before running each test to make sure it's
not affected by other tests outside
chrome/browser/ssl/tls_deprecation_config_unittest.cc

TBR= cthomp

Bug: 2141099
Change-Id: I1bf04ee46023b43796767ca7cf92c1bda0b69cb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2153437
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760043}

chrome/browser/ssl/tls_deprecation_config_unittest.cc

@@ -16,6 +16,7 @@ using chrome_browser_ssl::LegacyTLSExperimentConfig;
 
 class TLSDeprecationConfigTest : public testing::Test {
  protected:
+  void SetUp() override { ResetTLSDeprecationConfigForTesting(); }
   void TearDown() override { ResetTLSDeprecationConfigForTesting(); }
 };