Test timeout by platform as well

mobile/src/main/java/be/mygod/vpnhotspot/net/wifi/SoftApConfigurationCompat.kt

@@ -364,6 +364,8 @@ data class SoftApConfigurationCompat(
         fun testPlatformValidity(channels: SparseIntArray) = setChannelsCompat(staticBuilder, channels)
         @RequiresApi(30)
         fun testPlatformValidity(bssid: MacAddress) = setBssid(staticBuilder, bssid)
+        @RequiresApi(30)
+        fun testPlatformValidity(timeout: Long) = setShutdownTimeoutMillis(staticBuilder, timeout)
     }
 
     @Suppress("DEPRECATION")

mobile/src/main/java/be/mygod/vpnhotspot/net/wifi/WifiApDialogFragment.kt

@@ -293,9 +293,9 @@ class WifiApDialogFragment : AlertDialogFragment<WifiApDialogFragment.Arg, WifiA
         dialogView.passwordWrapper.error = if (passwordValid) null else " "
         val timeoutError = dialogView.timeout.text.let { text ->
             if (text.isNullOrEmpty()) null else try {
-                text.toString().toLong()
+                SoftApConfigurationCompat.testPlatformValidity(text.toString().toLong())
                 null
-            } catch (e: NumberFormatException) {
+            } catch (e: Exception) {
                 e.readableMessage
             }
         }