Modify package name to com.launchdarkly

[saraht129]

com.reactlibrary is a common name found in other packages as well, and having the same name will cause conflict on Android:

com.android.build.api.transform.TransformException: Error while generating the main dex list.
> Error while generating the main dex list.
  > com.android.tools.r8.errors.CompilationError: Program type already present: 
com.reactlibrary.BuildConfig
    > Program type already present: com.reactlibrary.BuildConfig

Issue: #11