Use std::filesystem for input event devices scan.

Use std::filesystem directory iterator to scan event devices in EventHub.

Bug: 160010896
Test: atest inputflinger_tests, atest EventHubTest
Change-Id: Ib5658e96783b8a1099fe0a2cb6dda51703045c84
diff --git a/services/inputflinger/reader/include/EventHub.h b/services/inputflinger/reader/include/EventHub.h
index c17f3a1..ee62c9a 100644
--- a/services/inputflinger/reader/include/EventHub.h
+++ b/services/inputflinger/reader/include/EventHub.h
@@ -373,13 +373,13 @@
         }
     };
 
-    status_t openDeviceLocked(const char* devicePath);
+    status_t openDeviceLocked(const std::string& devicePath);
     void openVideoDeviceLocked(const std::string& devicePath);
     void createVirtualKeyboardLocked();
     void addDeviceLocked(Device* device);
     void assignDescriptorLocked(InputDeviceIdentifier& identifier);
 
-    void closeDeviceByPathLocked(const char* devicePath);
+    void closeDeviceByPathLocked(const std::string& devicePath);
     void closeVideoDeviceByPathLocked(const std::string& devicePath);
     void closeDeviceLocked(Device* device);
     void closeAllDevicesLocked();
@@ -396,14 +396,14 @@
     status_t unregisterDeviceFromEpollLocked(Device* device);
     void unregisterVideoDeviceFromEpollLocked(const TouchVideoDevice& videoDevice);
 
-    status_t scanDirLocked(const char* dirname);
+    status_t scanDirLocked(const std::string& dirname);
     status_t scanVideoDirLocked(const std::string& dirname);
     void scanDevicesLocked();
     status_t readNotifyLocked();
 
     Device* getDeviceByDescriptorLocked(const std::string& descriptor) const;
     Device* getDeviceLocked(int32_t deviceId) const;
-    Device* getDeviceByPathLocked(const char* devicePath) const;
+    Device* getDeviceByPathLocked(const std::string& devicePath) const;
     /**
      * Look through all available fd's (both for input devices and for video devices),
      * and return the device pointer.