update wording earpiece -> headset

locales/de/app.json

@@ -175,7 +175,7 @@
       "camera_numbered": "Kamera {{n}}",
       "default": "Standard",
       "default_named": "Standard<2> ({{name}} )</2>",
-      "earpiece": "Ohrhörer",
+      "handset": "Ohrhörer",
       "microphone": "Mikrofon",
       "microphone_numbered": "Mikrofon{{n}}",
       "speaker": "Lautsprecher",

locales/en/app.json

@@ -79,10 +79,10 @@
     "use_to_device_key_transport": "Use to device key transport. This will fallback to room key transport when another call member sent a room key"
   },
   "disconnected_banner": "Connectivity to the server has been lost.",
-  "earpiece": {
+  "handset": {
     "overlay_back_button": "Back to Speaker Mode",
     "overlay_description": "Only works while using app",
-    "overlay_title": "Earpiece Mode"
+    "overlay_title": "Handset Mode"
   },
   "error": {
     "call_is_not_supported": "Call is not supported",
@@ -181,7 +181,7 @@
       "change_device_button": "Change audio device",
       "default": "Default",
       "default_named": "Default <2>({{name}})</2>",
-      "earpiece": "Earpiece",
+      "handset": "Handset",
       "loudspeaker": "Loudspeaker",
       "microphone": "Microphone",
       "microphone_numbered": "Microphone {{n}}",