[RN] Adjust button labels to reflext the actual state

lang/main.json

     "toolbar": {
         "addPeople": "Add people to your call",
         "audioonly": "Enable / Disable audio only mode (saves bandwidth)",
+        "audioOnlyOn": "Enable audio only mode (saves bandwidth)",
+        "audioOnlyOff": "Disable audio only mode",
         "audioRoute": "Select the audio route",
         "callQuality": "Manage call quality",
         "enterFullScreen": "View full screen",
         "reservationError": "Reservation system error",
         "reservationErrorMsg": "Error code: __code__, message: __msg__",
         "password": "Enter password",
+        "unlockRoom": "Unlock room",
         "userPassword": "user password",
         "token": "token",
         "tokenAuthFailedTitle": "Authentication failed",

react/features/room-lock/components/RoomLockButton.js

 class RoomLockButton extends AbstractButton<Props, *> {
     accessibilityLabel = 'Room lock';
     iconName = 'security';
-    label = 'toolbar.lock';
+    label = 'dialog.lockRoom';
     toggledIconName = 'security-locked';
+    toggledLabel = 'dialog.unlockRoom';
 
     /**
      * Handles clicking / pressing the button.

react/features/toolbox/components/native/AudioOnlyButton.js

 class AudioOnlyButton extends AbstractButton<Props, *> {
     accessibilityLabel = 'Audio only mode';
     iconName = 'visibility';
-    label = 'toolbar.audioonly';
+    label = 'toolbar.audioOnlyOn';
     toggledIconName = 'visibility-off';
+    toggledLabel = 'toolbar.audioOnlyOff';
 
     /**
      * Handles clicking / pressing the button.