[nrfconnect] Bring back BLE write requests (#7039)

PR #6955, apart from changing from BLE indications to
notifications on nRF Connect platform, started require
controllers to use WriteCommon (aka Write without response)
only as that is required by the spec.

However, Darwin platform layer still uses WriteRequest
(aka Write with response) method, so the change broke
compatibility between mac and nRF Connect platforms.

Support both methods on the firmware side.

src/platform/Zephyr/BLEManagerImpl.cpp

@@ -68,7 +68,7 @@ _bt_gatt_ccc CHIPoBLEChar_TX_CCC = BT_GATT_CCC_INITIALIZER(nullptr, BLEManagerIm
 BT_GATT_SERVICE_DEFINE(CHIPoBLE_Service,
     BT_GATT_PRIMARY_SERVICE(&UUID16_CHIPoBLEService.uuid),
         BT_GATT_CHARACTERISTIC(&UUID128_CHIPoBLEChar_RX.uuid,
-                               BT_GATT_CHRC_WRITE_WITHOUT_RESP,
+                               BT_GATT_CHRC_WRITE | BT_GATT_CHRC_WRITE_WITHOUT_RESP,
                                BT_GATT_PERM_READ | BT_GATT_PERM_WRITE,
                                nullptr, BLEManagerImpl::HandleRXWrite, nullptr),
         BT_GATT_CHARACTERISTIC(&UUID128_CHIPoBLEChar_TX.uuid,