Fix clang-tidy performance warnings in frameworks/base.

* Use more efficient overloaded string methods.

Bug: 30411878
Test: build with WITH_TIDY=1
Change-Id: Ia387e61770e1e7211280ed028ef0eef6e632a1d2
diff --git a/tools/incident_section_gen/main.cpp b/tools/incident_section_gen/main.cpp
index 3689a8f..4b5677a 100644
--- a/tools/incident_section_gen/main.cpp
+++ b/tools/incident_section_gen/main.cpp
@@ -140,7 +140,7 @@
     size_t base = 0;
     size_t found;
     while (true) {
-        found = args.find_first_of(" ", base);
+        found = args.find_first_of(' ', base);
         if (found != base) {
             string arg = args.substr(base, found - base);
             printf(" \"%s\",", arg.c_str());