fixes#18831
We update the nix derivation to build android by passing `hermesEnabled` flag which checks the environment variable and if the environment variable is not set we default `hermesEnabled` to `true`.
This ensures that `hermes` is disabled for debug builds and enabled for release builds.
In this commit we also
- rename `nix/mobile/android/release.nix` → `nix/mobile/android/build.nix` since that nix file no longer generates release only builds.
- cleanup 2 other env vars and use the `gradle` project format
- replace `BUILD_NUMBER` with `verisonCode` for consistency
- replace `androidGradleOpts ` with `buildUrl `
- bump `status-jenkins-lib` to v1.8.7
Siddarth Kumar