[mobile-install v3] Parse correct abi name from android platform

Mobile install v3 still has the same issue as https://github.com/bazelbuild/bazel/issues/15837

As of now, we have to hardcode the platform name to make it work
```
platform(
# name = "android_arm64", # This doesn't work
name = "arm64-v8a",
constraint_values = [
"@platforms//os:android",
"@platforms//cpu:arm64",
],
)
```

Start by reading the linked Bazel issue 15837 and locating the mobile-install v3 handling of Android platform names. Verify how the ABI is currently derived and make the platform use the correct ABI name without hardcoding it; the example platform definition provides the expected arm64-v8a result.

Written by the indexing model from the issue text.