init: Use std::string_view instead of std::string where appropriate

Slightly reduce the time that is required to start the init process by
changing two static std::string variables into std::string_view variables.

Change-Id: Ib683a603da5f3d8968b26453b12544fed8a6397f
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/init/devices.cpp b/init/devices.cpp
index e76786a..792d8c8 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -25,6 +25,7 @@
 #include <filesystem>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 
 #include <android-base/chrono_utils.h>
@@ -377,8 +378,8 @@
 
     if (FindPlatformDevice(uevent.path, &device)) {
         // Skip /devices/platform or /devices/ if present
-        static const std::string devices_platform_prefix = "/devices/platform/";
-        static const std::string devices_prefix = "/devices/";
+        static constexpr std::string_view devices_platform_prefix = "/devices/platform/";
+        static constexpr std::string_view devices_prefix = "/devices/";
 
         if (StartsWith(device, devices_platform_prefix)) {
             device = device.substr(devices_platform_prefix.length());