Remove jcenter references

[gare-bear]

jcenter has shutdown as of May 1st https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

Because of this, npx react-native run-android fails with the following error

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:checkDebugAarMetadata'.
> Could not resolve all files for configuration ':app:debugRuntimeClasspath'.
   > Could not resolve org.webkit:android-jsc:+.
     Required by:
         project :app
      > Failed to list versions for org.webkit:android-jsc.
         > Unable to load Maven meta-data from https://jcenter.bintray.com/org/webkit/android-jsc/maven-metadata.xml.
            > Could not HEAD 'https://jcenter.bintray.com/org/webkit/android-jsc/maven-metadata.xml'.
               > Read timed out

We should remove all references to jcenter to ensure we can continue to build this project on Android.