Fix clang-tidy performance-faster-string-find warnings

Bug: 30411878
Test: build with WITH_TIDY=1
Change-Id: I7fd815aa401fbcaff97b772f3ba5d6f1d2034011
diff --git a/tools/aapt2/dump/DumpManifest.cpp b/tools/aapt2/dump/DumpManifest.cpp
index 92f1ddb..42a6471 100644
--- a/tools/aapt2/dump/DumpManifest.cpp
+++ b/tools/aapt2/dump/DumpManifest.cpp
@@ -1175,7 +1175,7 @@
     }
 
     // Fully qualify the activity name
-    ssize_t idx = name.find(".");
+    ssize_t idx = name.find('.');
     if (idx == 0) {
       name = package + name;
     } else if (idx < 0) {
@@ -2125,7 +2125,7 @@
     size_t pos = file_path.find("lib/");
     if (pos != std::string::npos) {
       file_path = file_path.substr(pos + 4);
-      pos = file_path.find("/");
+      pos = file_path.find('/');
       if (pos != std::string::npos) {
         file_path = file_path.substr(0, pos);
       }
diff --git a/tools/aapt2/java/ManifestClassGenerator.cpp b/tools/aapt2/java/ManifestClassGenerator.cpp
index 10e504e..09ea03b 100644
--- a/tools/aapt2/java/ManifestClassGenerator.cpp
+++ b/tools/aapt2/java/ManifestClassGenerator.cpp
@@ -39,7 +39,7 @@
   }
 
   // Normalize only the java identifier, leave the original value unchanged.
-  if (result.find("-") != std::string::npos) {
+  if (result.find('-') != std::string::npos) {
     result = JavaClassGenerator::TransformToFieldName(result);
   }