Remove stetho (#762)

Summary:
## Summary

Resolves https://github.com/facebook/flipper/issues/607

This removes stetho dependencies directly in favor of just copying in the used classes. This removes the last non-androidx dependency from the project, and is useful as stetho appears to be unmaintained. The fresco stetho dependency appeared to be completely unused.

## Changelog

Remove stetho dependencies. It was unused other than a few utility methods, but came at the cost of preventing Flipper consumers from completely removing dependencies that hadn't updated to Androidx yet.
Pull Request resolved: https://github.com/facebook/flipper/pull/762

Test Plan: Existing tests still pass with no regressions. Functionally this should be no difference.

Reviewed By: jknoxville

Differential Revision: D19577969

Pulled By: passy

fbshipit-source-id: b277ddf97a9d2c846dd0b9227c02bb46c1ecd930

android/plugins/fresco/build.gradle

@@ -21,8 +21,12 @@ android {
         implementation project(':android')
         implementation deps.fresco
         implementation deps.frescoFlipper
-        implementation deps.frescoStetho
         compileOnly deps.jsr305
+
+        // Exclude the actual stetho dep as we only want some of the fresco APIs here
+        implementation(deps.frescoStetho) {
+            exclude group: 'com.facebook.stetho'
+        }
     }
 }