build(react-native): Update Gradle and AGP in preparation for dropping jcenter

[bengourley]

Goal

jcenter will be going away. Initially I tried to remove our reliance on jcenter for fixtures and examples, but not all of React Native's dependencies are available on Maven Central yet.

This PR just includes the gradle updates required, but doesn't drop jcenter just yet.

[github-actions[bot]]

@bugsnag/browser bundle size diff

	Minified	Minfied + Gzipped
Before	41.14 kB	12.66 kB
After	41.14 kB	12.66 kB
±	No change	No change

code coverage diff

Coverage values did not change👌.

Total:

Lines	Branches	Functions	Statements
0%(+0%)	0%(+0%)	0%(+0%)	0%(+0%)

Generated by :no_entry_sign: dangerJS against 734cecade76abc6e1eea06c274bec7dc3b041c72

[Udbhav12]

@bengourley Is there any update on this PR ? When will this get merged ?

[mattdyoung]

@Udbhav12 - we weren't originally able to progress this PR due to not all the dependencies being available, but we plan to pick it up again soon.

[Udbhav12]

@mattdyoung Thanks for update, Do we have any timelines for this ?

As per my understanding JCenter will completely shut down on February 1, 2022

https://blog.gradle.org/jcenter-shutdown