Enable TPMFirmwareUpdate feature by default.

BUG=chromium:775444
TEST=TPM firmware update offered in powerwash dialog even without finch config.

Change-Id: I533afd2306c6e5f8af943f81f4f15542cf7ba116
Reviewed-on: https://chromium-review.googlesource.com/c/1317896Reviewed-by: Rahul Chaturvedi <rkc@chromium.org>
Commit-Queue: Mattias Nissler <mnissler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605658}

chrome/common/chrome_features.cc

@@ -631,7 +631,7 @@ const base::Feature kCrOSComponent{"CrOSComponent",
 
 // Enables or disables TPM firmware update capability on Chrome OS.
 const base::Feature kTPMFirmwareUpdate{"TPMFirmwareUpdate",
-                                       base::FEATURE_DISABLED_BY_DEFAULT};
+                                       base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables or disables "usm" service in the list of user services returned by
 // userInfo Gaia message.