Mi Bands+Bip: when an operation finishes, unset the gatt callback on the BtLEQeue

Otherwise it will continue to receive events until another transaction is being executed.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/btle/AbstractBTLEOperation.java

@@ -85,6 +85,9 @@ public abstract class AbstractBTLEOperation<T extends AbstractBTLEDeviceSupport>
      * You MUST call this method when the operation has finished, either
      * successfully or unsuccessfully.
      *
+     * Subclasses must ensure that the {@link BtLEQueue queue's}'s gatt callback (set on the transaction builder by {@link #performInitialized(String)})
+     * is being unset, otherwise it will continue to receive events until another transaction is being executed by the queue.
+     *
      * @throws IOException
      */
     protected void operationFinished() throws IOException {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband/operations/AbstractMiBandOperation.java

@@ -48,6 +48,7 @@ public abstract class AbstractMiBandOperation<T extends AbstractBTLEDeviceSuppor
             try {
                 TransactionBuilder builder = performInitialized("reenabling disabled notifications");
                 handleFinished(builder);
+                builder.setGattCallback(null); // unset ourselves from being the queue's gatt callback
                 builder.queue(getQueue());
             } catch (IOException ex) {
                 GB.toast(getContext(), "Error enabling Mi Band notifications, you may need to connect and disconnect", Toast.LENGTH_LONG, GB.ERROR, ex);