fix: set the content to binding.root view

app/src/main/java/org/thoughtcrime/securesms/calls/WebRtcCallActivity.kt

@@ -81,6 +81,7 @@ class WebRtcCallActivity : PassphraseRequiredActionBarActivity() {
     override fun onCreate(savedInstanceState: Bundle?, ready: Boolean) {
         super.onCreate(savedInstanceState, ready)
         binding = ActivityWebrtcBinding.inflate(layoutInflater)
+        setContentView(binding.root)
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
             setShowWhenLocked(true)
             setTurnScreenOn(true)