Enable cppcoreguidelines-avoid-c-arrays

We only had one pretty trivial use of a C array in dbus-sensors.
Replace that with std::array, and enable the checks.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I5ecbfa07a7f46977dc3ccbde3c4b385e95b6a730
diff --git a/.clang-tidy b/.clang-tidy
index 8932c14..001c11a 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -187,6 +187,7 @@
 clang-analyzer-valist.ValistBase,
 clang-analyzer-webkit.NoUncountedMemberChecker,
 clang-analyzer-webkit.RefCntblBaseVirtualDtor,
+cppcoreguidelines-avoid-c-arrays,
 cppcoreguidelines-init-variables,
 misc-misplaced-const,
 misc-no-recursion,