Use `tidy_checks_as_errors` list instead of `-warnings-as-errors=*`

This fixes a build break due to new code from
http://ag/I96f970e82b5243be01b205ac2cb6ab249c6100bc that inadvertently
triggers some false positives with other clang-tidy flags. Builds that
use a wider set of tidy flags (as specified in the test below) will
break since `-warnings-as-errors=*` turns all warnings into errors,
rather than just the ones that were specified as part of this
Android.bp. The preferred way of checking this is to use
`tidy_checks_as_errors`

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: I941b3c89402e2cfa290b3829e2ac8ff7ea67ca3d