Add readOnly state access to LocalJtxCollection

Author: sunkup

app/src/main/kotlin/at/bitfire/davdroid/resource/LocalJtxCollection.kt

@@ -51,8 +51,13 @@ class LocalJtxCollection(account: Account, client: ContentProviderClient, id: Lo
     }
 
     override var readOnly: Boolean
-        get() = TODO("Not yet implemented")
-        set(value) {}
+        get() {
+            Logger.log.log(Level.INFO, "No access to read-only state of JtxCollection. Assuming write access.")
+            return false
+        }
+        set(value) {
+            Logger.log.log(Level.INFO, "No access to read-only state of JtxCollection. Did not set value.")
+        }
 
     override val tag: String
         get() =  "jtx-${account.name}-$id"