Add back missing `tidy_checks`, since `tidy_checks_as_errors` isn't enough

I unfortunately missed in the original testing that
`tidy_checks_as_errors` isn't sufficient by itself. Instead we need to
have both places with the same variables. A future change will make
Soong expand `tidy_checks_as_errors` into both locations appropriately.

Bug: 119328308
Test: WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=*,-readability-*,-google-readability-*,-google-runtime-references,-cppcoreguidelines-*,-modernize-*,-llvm-*,-bugprone-narrowing-conversions,-misc-non-private-member-variables-in-classes,-misc-unused-parameters,-hicpp-*,-fuchsia-* mm
Change-Id: If69f69bf7861ba3569756270381f3f737366f2f0
Merged-In: If69f69bf7861ba3569756270381f3f737366f2f0
(cherry picked from commit 56af5939)