bluetooth: Add BluetoothGATTCharacteristic IDL and Blink interface

Source/modules/modules.gypi

 {
   'includes': [
     '../core/core_generated.gypi',
     'modules_generated.gypi',
   ],
   'variables': {
     # Experimental hooks for embedder to provide extra IDL and source files.
     #
     # Note: this is not a supported API. If you rely on this, you will be broken
     # from time to time as the code generator changes in backward incompatible
     # ways.
     'extra_blink_module_idl_files': [],
     'extra_blink_module_files': [],
     # Files for which bindings (.cpp and .h files) will be generated
     'modules_idl_files': [
       '<@(extra_blink_module_idl_files)',
       'app_banner/AppBannerPromptResult.idl',
       'app_banner/BeforeInstallPromptEvent.idl',
       'background_sync/PeriodicSyncEvent.idl',
       'background_sync/PeriodicSyncManager.idl',
       'background_sync/PeriodicSyncRegistration.idl',
       'background_sync/SyncEvent.idl',
       'background_sync/SyncManager.idl',
       'background_sync/SyncRegistration.idl',
       'battery/BatteryManager.idl',
       'bluetooth/Bluetooth.idl',
       'bluetooth/BluetoothDevice.idl',
+      'bluetooth/BluetoothGATTCharacteristic.idl',
       'bluetooth/BluetoothGATTRemoteServer.idl',
       'bluetooth/BluetoothGATTService.idl',
       'cachestorage/Cache.idl',
       'cachestorage/CacheStorage.idl',
       'compositorworker/CompositorWorker.idl',
       'compositorworker/CompositorWorkerGlobalScope.idl',
       'credentialmanager/Credential.idl',
       'credentialmanager/CredentialsContainer.idl',
       'credentialmanager/FederatedCredential.idl',
       'credentialmanager/LocalCredential.idl',
@@ skipping 557 matching lines @@
       'battery/NavigatorBattery.cpp',
       'battery/NavigatorBattery.h',
       'beacon/NavigatorBeacon.cpp',
       'beacon/NavigatorBeacon.h',
       'bluetooth/Bluetooth.h',
       'bluetooth/Bluetooth.cpp',
       'bluetooth/BluetoothDevice.cpp',
       'bluetooth/BluetoothDevice.h',
       'bluetooth/BluetoothError.cpp',
       'bluetooth/BluetoothError.h',
+      'bluetooth/BluetoothGATTCharacteristic.h',
       'bluetooth/BluetoothGATTService.h',
       'bluetooth/BluetoothGATTService.cpp',
       'bluetooth/BluetoothGATTRemoteServer.h',
       'bluetooth/BluetoothGATTRemoteServer.cpp',
       'bluetooth/NavigatorBluetooth.cpp',
       'bluetooth/NavigatorBluetooth.h',
       'cachestorage/Cache.cpp',
       'cachestorage/Cache.h',
       'cachestorage/CacheStorage.cpp',
       'cachestorage/CacheStorage.h',
@@ skipping 824 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }