Revert wallet back to non-indexer RPC (MystenLabs#16940)

## Description 

Describe the changes or additions included in this PR.

## Test Plan 

How did you test the new or updated feature?

---
If your changes are not user-facing and do not break anything, you can
skip the following section. Otherwise, please briefly describe what has
changed under the Release Notes section.

### Type of Change (Check all that apply)

- [ ] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes

apps/wallet/configs/environment/.env.defaults

@@ -5,8 +5,8 @@ API_ENV=mainnet
 API_ENDPOINT_LOCAL=http://127.0.0.1:5001/
 API_ENDPOINT_LOCAL_FULLNODE=http://127.0.0.1:9000/
 API_ENDPOINT_LOCAL_FAUCET=http://127.0.0.1:9123/gas
-API_ENDPOINT_DEV_NET_FULLNODE=https://sui-devnet.mystenlabs.com/json-rpc
+API_ENDPOINT_DEV_NET_FULLNODE=https://wallet-rpc.devnet.sui.io/
 API_ENDPOINT_DEV_NET_FAUCET=https://faucet.devnet.sui.io/gas
-API_ENDPOINT_TEST_NET_FULLNODE=https://sui-testnet.mystenlabs.com/json-rpc
+API_ENDPOINT_TEST_NET_FULLNODE=https://wallet-rpc.testnet.sui.io/
 API_ENDPOINT_TEST_NET_FAUCET=https://faucet.testnet.sui.io/gas
-API_ENDPOINT_MAINNET_FULLNODE=https://sui-mainnet.mystenlabs.com/json-rpc
+API_ENDPOINT_MAINNET_FULLNODE=https://wallet-rpc.mainnet.sui.io/