Enable google-default-arguments clang-tidy check

Following this discussion on cxx[1], this CL enables
google-default-arguments clang-tidy check in Tricium.

[1] https://groups.google.com/u/1/a/chromium.org/g/cxx/c/xLrKjHfvf8E

Bug: 1513346
Change-Id: I14e074fda3c20512d53699175b10ab48fffdf886
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5138982
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1242754}

diff --git a/.clang-tidy b/.clang-tidy
index 00c9662..743f957 100644
--- a/.clang-tidy
+++ b/.clang-tidy

@@ -12,6 +12,7 @@
                     bugprone-unused-raii,
                     bugprone-use-after-move,
                     google-build-explicit-make-pair,
+                    google-default-arguments,
                     google-explicit-constructor,
                     google-objc-avoid-nsobject-new,
                     misc-misleading-identifier,