use cross as Back button at the event activity

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt

@@ -108,7 +108,6 @@ class EventActivity : SimpleActivity() {
             return
         }
 
-        supportActionBar?.setHomeAsUpIndicator(R.drawable.ic_cross_vector)
         val intent = intent ?: return
         mDialogTheme = getDialogTheme()
         mWasContactsPermissionChecked = hasPermission(PERMISSION_READ_CONTACTS)
@@ -253,7 +252,7 @@ class EventActivity : SimpleActivity() {
             menu.findItem(R.id.duplicate).isVisible = mEvent.id != null
         }
 
-        updateMenuItemColors(menu)
+        updateMenuItemColors(menu, true)
         return true
     }