tonic-build: Codegen generates a name collision after auto-capitalization is applied, resulting in cargo build errors

## Bug Report

### Version

└── tonic v0.11.0
└── tonic-build v0.11.0

### Platform

Linux enceladus 5.15.146.1-microsoft-standard-WSL2 #1 SMP Thu Jan 11 04:09:03 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

### Crates

`tonic-build`

### Description

I'm trying to build protos for Cosmos using tonic-build.

One of the [proto files](https://github.com/cosmos/cosmos-sdk/blob/main/x/staking/proto/cosmos/staking/v1beta1/authz.proto) contains both names `validators` and `Validators`:

```
message StakeAuthorization {
option (cosmos_proto.implements_interface) = "cosmos.authz.v1beta1.Authorization";
option (amino.name) = "cosmos-sdk/StakeAuthorization";

// max_tokens specifies the maximum amount of tokens can be delegate to a validator. If it is
// empty, there is no spend limit and any amount of coins can be delegated.
cosmos.base.v1beta1.Coin max_tokens = 1 [(gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coin"];
// validators is the oneof that represents either allow_list or deny_list
oneof validators {
// allow_list specifies list of validator addresses to whom grantee can delegate tokens on behalf of granter's
// account.
Validators allow_list = 2 [(amino.oneof_name) = "cosmos-sdk/StakeAuthorization/AllowList"];
// deny_list specifies list of validator addresses to whom grantee can not delegate tokens.
Validators deny_list = 3 [(amino.oneof_name) = "cosmos-sdk/StakeAuthorization/DenyList"];
}
// Validators defines list of validator addresses.
message Validators {
repeated string address = 1 [(cosmos_proto.scalar) = "cosmos.AddressString"];
}
// authorization_type defines one of AuthorizationType.
AuthorizationType authorization_type = 4;
}
```

Because of auto-capitalization, the generated Rust includes two types both with the name `Validators`:

```
/// Nested message and enum types in `StakeAuthorization`.
pub mod stake_authorization {
/// Validators defines list of validator addresses.
#[allow(clippy::derive_partial_eq_without_eq)]
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct ValidatorList {
#[prost(string, repeated, tag = "1")]
pub address: ::prost::alloc::vec::Vec<::prost::alloc::string::String>,
}
/// validators is the oneof that represents either allow_list or deny_list
#[allow(clippy::derive_partial_eq_without_eq)]
#[derive(Clone, PartialEq, ::prost::Oneof)]
pub enum Validators {
/// allow_list specifies list of validator addresses to whom grantee can delegate tokens on behalf of granter's
/// account.
#[prost(message, tag = "2")]
AllowList(Validators),
/// deny_list specifies list of validator addresses to whom grantee can not delegate tokens.
#[prost(message, tag = "3")]
DenyList(Validators),
}
}
```

This causes `cargo build` to fail with errors:

```
error[E0428]: the name `Validators` is defined multiple times
--> /home/lumi/code/rust-dydx-protos/target/debug/build/rust-dydx-protos-2059e937180aa0c5/out/cosmos.staking.v1beta1.rs:31:5
|
24 | pub struct Validators {
| --------------------- previous definition of the type `Validators` here
...
31 | pub enum Validators {
| ^^^^^^^^^^^^^^^^^^^ `Validators` redefined here
|
= note: `Validators` must be defined only once in the type namespace of this module
```

By monkey patching the .proto to use the name `ValidatorList` instead of `Validators` I can get the build to succeed. But I'm wondering if there is any solution within `tonic-build` to deal with this.