MainActivity fixes (#6591)

* Reduce notifyDataSetChanged calls when category count is disabled

* Fix category tabs briefly showing when it's supposed to be disabled

Also fix tabs showing when activity recreated

* Lift appbar when tab is hidden

Check against tab visibility instead of viewpager

* Restore selected nav item after recreate

* Simplify SHORTCUT_MANGA intent handling

Don't need to change controller if the topmost controller is the target

app/src/main/java/eu/kanade/tachiyomi/ui/browse/BrowseController.kt

@@ -79,11 +79,12 @@ class BrowseController :
         }
     }
 
-    override fun configureTabs(tabs: TabLayout) {
+    override fun configureTabs(tabs: TabLayout): Boolean {
         with(tabs) {
             tabGravity = TabLayout.GRAVITY_FILL
             tabMode = TabLayout.MODE_FIXED
         }
+        return true
     }
 
     override fun cleanupTabs(tabs: TabLayout) {