Incorrect version for aws-cryptographic-material-providers in README

**Summary**

The README for the AWS Encryption SDK Java lists the following dependency:

```xml

software.amazon.cryptography
aws-cryptographic-material-providers
3.0.2

```

However, version **3.0.2 does not exist on Maven Central**.
The latest available version is 1.11.0 as can be seen in the image below

**Suggested fix**
Update the README to use a valid version:

```xml
1.11.0
```

Open the README and locate the aws-cryptographic-material-providers dependency shown in the issue. Verify the listed version against Maven Central, update it to 1.11.0, and confirm the dependency example now uses a valid version.

Written by the indexing model from the issue text.