generators: Remove dependency on protos strutil.h

The strutil.h header is not part of the protobuf API
and is removed from later version of protobuf.
Use base::StringUtils instead. Change is reasonably
safe as it affects only tools used at build-time
(the protobuf generators).

Bug: 140126865
Test: check 0-diff in out/xxx/gen/
Change-Id: Iacd1340183e92a6d10f0d033de16bc75ed39013d
diff --git a/Android.bp b/Android.bp
index 73cbcec..5d6e701 100644
--- a/Android.bp
+++ b/Android.bp
@@ -3689,6 +3689,23 @@
 cc_binary_host {
   name: "perfetto_src_ipc_protoc_plugin_ipc_plugin___gn_standalone_toolchain_gcc_like_host_",
   srcs: [
+    "src/base/event_fd.cc",
+    "src/base/file_utils.cc",
+    "src/base/metatrace.cc",
+    "src/base/paged_memory.cc",
+    "src/base/pipe.cc",
+    "src/base/string_splitter.cc",
+    "src/base/string_utils.cc",
+    "src/base/string_view.cc",
+    "src/base/temp_file.cc",
+    "src/base/thread_checker.cc",
+    "src/base/thread_task_runner.cc",
+    "src/base/time.cc",
+    "src/base/unix_task_runner.cc",
+    "src/base/uuid.cc",
+    "src/base/virtual_destructors.cc",
+    "src/base/waitable_event.cc",
+    "src/base/watchdog_posix.cc",
     "src/ipc/protoc_plugin/ipc_plugin.cc",
   ],
   shared_libs: [
@@ -3791,6 +3808,23 @@
 cc_binary_host {
   name: "perfetto_src_protozero_protoc_plugin_protozero_plugin___gn_standalone_toolchain_gcc_like_host_",
   srcs: [
+    "src/base/event_fd.cc",
+    "src/base/file_utils.cc",
+    "src/base/metatrace.cc",
+    "src/base/paged_memory.cc",
+    "src/base/pipe.cc",
+    "src/base/string_splitter.cc",
+    "src/base/string_utils.cc",
+    "src/base/string_view.cc",
+    "src/base/temp_file.cc",
+    "src/base/thread_checker.cc",
+    "src/base/thread_task_runner.cc",
+    "src/base/time.cc",
+    "src/base/unix_task_runner.cc",
+    "src/base/uuid.cc",
+    "src/base/virtual_destructors.cc",
+    "src/base/waitable_event.cc",
+    "src/base/watchdog_posix.cc",
     "src/protozero/protoc_plugin/protozero_plugin.cc",
   ],
   shared_libs: [