Fix clang-tidy performance warnings in system/core.

* Use const reference parameter type to avoid unnecessary copy.
* Use more efficient overloaded string methods.

Bug: 30407689
Bug: 30411878
Test: build with WITH_TIDY=1
Change-Id: Ia5a00581e718d412255d6177e5a7c286cdfbec11
2 files changed
tree: 3fd9fc4e7a25431a91987c8467f4f722eacdaef5
  1. liblog/
  2. logcat/
  3. logd/
  4. logwrapper/