resolve stack overflow when showing/hiding omnibar (#7023)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/414730916066338/task/1211782850017596?focus=true

### Description
Resolve a regression where function invocation changed from an extension
to recursion during a refactor in
#6983.

### Steps to test this PR

- [x] Open the app.
- [x] Search and go to videos.
- [x] Start a video.
- [x] Open full screen.
- [x] Close full screen.

Author: LukasPaczos

app/src/main/java/com/duckduckgo/app/browser/omnibar/LegacyOmnibarLayout.kt

@@ -999,11 +999,11 @@ open class LegacyOmnibarLayout @JvmOverloads constructor(
     }
 
     override fun show() {
-        show()
+        visibility = View.VISIBLE
     }
 
     override fun gone() {
-        gone()
+        visibility = View.GONE
     }
 }
 

app/src/main/java/com/duckduckgo/app/browser/omnibar/OmnibarLayout.kt

@@ -1175,10 +1175,10 @@ class OmnibarLayout @JvmOverloads constructor(
     }
 
     override fun show() {
-        show()
+        visibility = View.VISIBLE
     }
 
     override fun gone() {
-        gone()
+        visibility = View.GONE
     }
 }