Fix clang-tidy performance warnings in syste/core.

* Use const reference type for parameters to avoid unnecessary copy.
* Suppress warning of not using faster overloaded string find function.

Bug: 30407689
Bug: 30411878
Change-Id: I6cfdbbd50cf5e8f3db6e5263076d3a17a9a791ee
Test: build with WITH_TIDY=1
Merged-In: Ie79dbe21899867bc62031f8618bb1322b8071525
diff --git a/init/service.cpp b/init/service.cpp
index f67af2d..44d9d8c 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -850,7 +850,7 @@
     return nullptr;
 }
 
-void ServiceManager::ForEachService(std::function<void(Service*)> callback) const {
+void ServiceManager::ForEachService(const std::function<void(Service*)>& callback) const {
     for (const auto& s : services_) {
         callback(s.get());
     }