Analytics - Data mismatch between CustomProperties and Pinpoint Attributes

### Before opening, please confirm:

- [X] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-android/issues?q=is%3Aissue+) and [discussions](https://github.com/aws-amplify/amplify-android/discussions).

### Language and Async Model

Not applicable

### Amplify Categories

Analytics, Notifications

### Gradle script dependencies

```groovy
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```

### Environment information

```
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```

### Please include any relevant guides or documentation you're referencing

_No response_

### Describe the feature request

We need to allow the update of user attributes to accept an array of values, similar to what is mentioned in this Github issue https://github.com/aws-amplify/amplify-flutter/issues/2850

### Initialization steps (if applicable)

_No response_

### Code Snippet

```java
// Put your code below this line.

```

### amplifyconfiguration.json

_No response_

### GraphQL Schema

```graphql
// Put your schema below this line

```

### Additional information and screenshots

Proposal:

Allow the Pinpoint Endpoint attributes field to be set as a Map in UserProfile by:

- Removing the UserProfile.customProperties field
- Adding UserProfile.attributes of type Map
- Adding UserProfile.metrics of type Map

Start by locating the Java UserProfile model and the Pinpoint Endpoint attributes integration in the Analytics and Notifications categories. Review how customProperties is currently represented and propagated, then determine the API and compatibility implications of replacing it with attributes as Map and adding metrics as Map. Done means user attribute arrays are accepted and the proposed Pinpoint representation is consistent.

Written by the indexing model from the issue text.