Fix onBackPressed() deprecation in NavigationDrawerActivity

Created a back callback for closing the drawer and connected it to the
drawer's listener to enable and disable it dynamically.

The code was added to initNavigationDrawer method which all screens
that appear in the drawer(DeckPicker, CardBrowser and Reviewer) call
in onCreate().

Having both the drawer opening and the back gesture happening on
swipe from the screen's left edge isn't great.

AnkiDroid/src/main/java/com/ichi2/anki/NavigationDrawerActivity.kt

@@ -24,6 +24,7 @@ import android.view.KeyEvent
 import android.view.LayoutInflater
 import android.view.MenuItem
 import android.view.View
+import androidx.activity.OnBackPressedCallback
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.LayoutRes
 import androidx.annotation.VisibleForTesting
@@ -142,6 +143,12 @@ abstract class NavigationDrawerActivity :
             // Decide which action to take when the navigation button is tapped.
             toolbar.setNavigationOnClickListener { onNavigationPressed() }
         }
+        val drawerBackCallback = object : OnBackPressedCallback(isDrawerOpen) {
+            override fun handleOnBackPressed() {
+                closeDrawer()
+            }
+        }
+        onBackPressedDispatcher.addCallback(drawerBackCallback)
         // ActionBarDrawerToggle ties together the the proper interactions
         // between the sliding drawer and the action bar app icon
         drawerToggle = object : ActionBarDrawerToggle(
@@ -154,7 +161,7 @@ abstract class NavigationDrawerActivity :
             override fun onDrawerClosed(drawerView: View) {
                 super.onDrawerClosed(drawerView)
                 invalidateOptionsMenu()
-
+                drawerBackCallback.isEnabled = false
                 // If animations are disabled, this is executed before onNavigationItemSelected is called
                 // PERF: May be able to reduce this delay
                 HandlerUtils.postDelayedOnNewHandler({
@@ -168,6 +175,7 @@ abstract class NavigationDrawerActivity :
             override fun onDrawerOpened(drawerView: View) {
                 super.onDrawerOpened(drawerView)
                 invalidateOptionsMenu()
+                drawerBackCallback.isEnabled = true
             }
         }
         if (drawerLayout is ClosableDrawerLayout) {
@@ -265,17 +273,6 @@ abstract class NavigationDrawerActivity :
             }
         }
 
-    @Suppress("deprecation") // onBackPressed
-    @Deprecated("Deprecated in Java")
-    override fun onBackPressed() {
-        if (isDrawerOpen) {
-            Timber.i("Back key pressed")
-            closeDrawer()
-        } else {
-            super.onBackPressed()
-        }
-    }
-
     /**
      * Called, when navigation button of the action bar is pressed.
      * Design pattern: template method. Subclasses can override this to define their own behaviour.