Attempt to get back button working

app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
+        android:enableOnBackInvokedCallback="true"
         android:theme="@style/AppTheme">
         <activity
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|smallestScreenSize|screenLayout|uiMode"

app/src/main/java/org/mapcomplete/Databridge.java

@@ -26,6 +26,10 @@ public class Databridge extends Plugin {
     }
 
     public static void sendAnswerTo(PluginCall call, String answer) {
+        if(call == null) {
+            System.err.println("Could not send an answer to a plugincall, is null");
+            return;
+        }
         JSObject ret = new JSObject();
         ret.put("value", answer);
         Log.i("databridge", "Resolving call");

variables.gradle

@@ -1,5 +1,5 @@
 ext {
-    minSdkVersion = 24
+    minSdkVersion = 33
     compileSdkVersion = 34
     targetSdkVersion = 34
     androidxActivityVersion = '1.8.0'