[FR] make RC-status of releases a real part of the NDK

### Description

I need to download the latest one automatically with .

```bash
#!/bin/bash

# Get the latest release tag from the remote repository
latest_tag=$(git ls-remote --tags https://github.com/android/ndk.git | awk -F'/' '{print $NF}' | sort -V | tail -n1)

# Store the tag in the variable
ANDROIDNDKVERSION=$latest_tag

# Print the variable to verify
echo "The latest release tag is: $ANDROIDNDKVERSION"
```

https://github.com/android/ndk/releases/tag/r28-rc2

This correlates to https://dl.google.com/android/repository/android-ndk-r28-beta3-linux.zip not https://dl.google.com/android/repository/android-ndk-r28-rc2-linux.zip

while

https://github.com/android/ndk/releases/tag/r28-beta1
is the name as its download file name.

### I am using a supported NDK

- [x] I have checked and the NDK I'm using is currently supported

### Affected versions

r28

Start by comparing the r28-rc2 and r28-beta1 release tags with their corresponding download URLs, as shown in the issue. Trace the NDK release metadata or publishing entry point responsible for this mapping; done means RC releases resolve to download filenames that include the RC status consistently.

Written by the indexing model from the issue text.