android: add setting to enable debug logs

If enabled, we log to stderr, which can get inspected via logcat.
Not user-friendly at all - but previously there was no way to get logs from a release build.

closes https://github.com/spesmilo/electrum/issues/7409

electrum/gui/qml/components/Preferences.qml

@@ -235,6 +235,17 @@ Pane {
                         }
                     }
 
+                    Switch {
+                        id: enableDebugLogs
+                        text: qsTr('Enable debug logs (for developers)')
+                        Layout.columnSpan: 2
+                        onCheckedChanged: {
+                            if (activeFocus)
+                                Config.enableDebugLogs = checked
+                        }
+                        enabled: Config.canToggleDebugLogs
+                    }
+
                 }
 
             }
@@ -257,6 +268,7 @@ Pane {
         spendUnconfirmed.checked = Config.spendUnconfirmed
         lnRoutingType.currentIndex = Config.useGossip ? 0 : 1
         useFallbackAddress.checked = Config.useFallbackAddress
+        enableDebugLogs.checked = Config.enableDebugLogs
         useRbf.checked = Config.useRbf
     }
 }