move onto AndroidX

[hnljp]

Migrated from the deprecated Android Support libraries to the newest versions of the AndroidX libraries.
The Android gradle plugin is updated to the current 4.0.0.
Glide is updated to the current 4.11.0, and 4.1x.x is needed for AndroidX support.

[hnljp]

@iainmcgin In case you are not able to get the OpenID CLA for #508 have I created my own pullrequest.
All dependencies (except the test ones) have been updated and I am supporting Android API 30.
Have also added a comment on getting AppAuth to work on Android 11.

[hnljp]

This PR documents Android 11 support: #554
Fixes:

• Android X support #417
• No matter what I do all browsers return false for useCustomTab #423
• Crash on net.openid.appauth.browser.CustomTabManager.onCustomTabsServiceConnected #425

[blundell]

@hnljp it's a bit cold to just take someones changes contributed in an effort to help an oss project and reauthor them as your own. I've signed all the CLA's its just a waiting game.

[hnljp]

@hnljp it's a bit cold to just take someones changes contributed in an effort to help an oss project and reauthor them as your own. I've signed all the CLA's its just a waiting game.

I did not copy your code, I made a new pull request from the ground.
I am happy that you have signed to CLA's, so I will close the this pull request.