[lib] Make displayFailureAlert optional in BaseEditUserAvatar

Summary:
`displayFailureAlert` is native-specific functionality which we won't implement for `web`.

We previously had an implementation using `alert(...)`, but showing a browser alert was not consistent with the rest of `web`'s error handling. It makes sense to have `displayFailureAlert` be optional and only implement it for `native`. Later in the stack we will handle this from `native/.../avatar-hooks.js` instead.

NOTE: The higher level goal with this (and subsequent) refactor(s) is for `[web/native]/.../avatar-hooks.react.js` to be platform-specific and entity(user vs. thread)-agnostic AND for `edit-*-avatar-provider.react.js` to be platform-agnostic and entity-specific. Right now there's some coupling between the two that makes implementation of image avatars on `web` pretty difficult... will work on cleaning things up in this stack. TLDR: avatar providers will be common interface between client and keyserver and avatar hooks will be platform-specific implementations to get things from platform-specific types (eg `MediaLibrarySelection`) to platform-agnostic types (eg `UpdateUserAvatarRequest`) so they can be passed to API provided by providers.

---

Depends on D8315

Test Plan: Alerts continue to appear as expected on `native`. Alerts continue NOT to appear on `web` as expected.

Reviewers: ashoat, ginsu, rohan

Reviewed By: ginsu

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D8316

lib/components/base-edit-user-avatar-provider.react.js

@@ -50,7 +50,7 @@ const updateUserAvatarLoadingStatusSelector = createLoadingStatusSelector(
 );
 
 type Props = {
-  +displayFailureAlert: () => mixed,
+  +displayFailureAlert?: () => mixed,
   +selectFromGallery: () => Promise<?MediaLibrarySelection>,
   +useUploadSelectedMedia: (
     setProcessingOrUploadInProgress?: (inProgress: boolean) => mixed,
@@ -106,7 +106,7 @@ function BaseEditUserAvatarProvider(props: Props): React.Node {
         try {
           return await updateUserAvatarCall(imageAvatarUpdateRequest);
         } catch (e) {
-          displayFailureAlert();
+          displayFailureAlert && displayFailureAlert();
           throw e;
         }
       })();
@@ -144,7 +144,7 @@ function BaseEditUserAvatarProvider(props: Props): React.Node {
         try {
           return await updateUserAvatarCall(request);
         } catch (e) {
-          displayFailureAlert();
+          displayFailureAlert && displayFailureAlert();
           throw e;
         }
       })();

web/avatars/web-edit-user-avatar-provider.react.js

@@ -4,8 +4,6 @@ import * as React from 'react';
 
 import { BaseEditUserAvatarProvider } from 'lib/components/base-edit-user-avatar-provider.react.js';
 
-const displayAvatarUpdateFailureAlert = () => null;
-
 // TODO: Implement `selectFromGallery(...)` for `web`.
 const selectFromGallery = async () => null;
 
@@ -19,7 +17,6 @@ function WebEditUserAvatarProvider(props: Props): React.Node {
   const { children } = props;
   return (
     <BaseEditUserAvatarProvider
-      displayFailureAlert={displayAvatarUpdateFailureAlert}
       selectFromGallery={selectFromGallery}
       useUploadSelectedMedia={useUploadSelectedMedia}
     >