simplify kotlin native module update

android/src/main/java/expo/modules/xmtpreactnativesdk/wrappers/GroupWrapper.kt

@@ -9,7 +9,7 @@ class GroupWrapper {
 
     companion object {
         fun encodeToObj(client: Client, group: Group): Map<String, Any> {
-            val permissionPolicySet = PermissionPolicySetWrapper.encodeToObj(group.permissionPolicySet())
+            val permissionPolicySet = PermissionPolicySetWrapper.encodeToJsonString(group.permissionPolicySet())
             return mapOf(
                 "clientAddress" to client.address,
                 "id" to group.id.toHex(),
@@ -31,4 +31,4 @@ class GroupWrapper {
             return gson.toJson(obj)
         }
     }
-}
+}

android/src/main/java/expo/modules/xmtpreactnativesdk/wrappers/PermissionPolicySetWrapper.kt

@@ -0,0 +1,37 @@
+package expo.modules.xmtpreactnativesdk.wrappers
+
+import com.google.gson.GsonBuilder
+import uniffi.xmtpv3.org.xmtp.android.library.libxmtp.PermissionOption
+import uniffi.xmtpv3.org.xmtp.android.library.libxmtp.PermissionPolicySet
+
+class PermissionPolicySetWrapper {
+
+    companion object {
+        fun fromPermissionOption(permissionOption: PermissionOption): String {
+            return when (permissionOption) {
+                PermissionOption.Allow -> "allow"
+                PermissionOption.Deny -> "deny"
+                PermissionOption.Admin -> "admin"
+                PermissionOption.SuperAdmin -> "superAdmin"
+                PermissionOption.Unknown -> "unknown"
+            }
+        }
+        fun encodeToObj(policySet: PermissionPolicySet): Map<String, Any> {
+            return mapOf(
+                "addMemberPolicy" to fromPermissionOption(policySet.addMemberPolicy),
+                "removeMemberPolicy" to fromPermissionOption(policySet.removeMemberPolicy),
+                "addAdminPolicy" to fromPermissionOption(policySet.addAdminPolicy),
+                "removeAdminPolicy" to fromPermissionOption(policySet.removeAdminPolicy),
+                "updateGroupNamePolicy" to fromPermissionOption(policySet.updateGroupNamePolicy),
+                "updateGroupDescriptionPolicy" to fromPermissionOption(policySet.updateGroupDescriptionPolicy),
+                "updateGroupImagePolicy" to fromPermissionOption(policySet.updateGroupImagePolicy),
+            )
+        }
+
+        fun encodeToJsonString(policySet: PermissionPolicySet): String {
+            val gson = GsonBuilder().create()
+            val obj = encodeToObj(policySet)
+            return gson.toJson(obj)
+        }
+    }
+}