Nullability Annotations to Java Classes - DialogFragment - Replace `findViewById` with `ViewBinding`

[ParaskP7]

Parent #18911

This issue is about adding replacing findViewById(...) with ViewBinding to as many Java-related DialogFragment classes as possible.

Instead of adding missing nullability annotations (@Nullable & @NonNull) to layout View related fields on such Java-related DialogFragment classes, it is better to migrate those fields, from the old way of assigning those (using findViewById(...)), and into the new way of referencing such view (direct via ViewBinding.

FYI: You could reference #14845 to get an idea on how to go about that.

---

### Tasks (`libs/editor`)
- [x] [ImageSettingsDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/libs/editor/src/main/java/org/wordpress/android/editor/ImageSettingsDialogFragment.java#L69)
- [ ] [LinkDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/libs/editor/src/main/java/org/wordpress/android/editor/LinkDialogFragment.java#L17)

### Tasks (`WordPress` + `ui.people`)
- [ ] [RoleChangeDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/people/RoleChangeDialogFragment.java#L30)
- [x] [RoleSelectDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/people/RoleSelectDialogFragment.java#L4)

### Tasks (`WordPress` + `ui.posts`)
- [ ] [AddCategoryFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/posts/AddCategoryFragment.java#L4)
- [ ] [InsertMediaDialog.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/posts/InsertMediaDialog.java#L4)
- [ ] [PostSettingsInputDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/posts/PostSettingsInputDialogFragment.java#L25)
- [x] [PostSettingsListDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/posts/PostSettingsListDialogFragment.java#L4)

### Tasks (`WordPress` + `ui.publicize`)
- [ ] [PublicizeAccountChooserDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/publicize/PublicizeAccountChooserDialogFragment.java#L33)

### Tasks (`WordPress` + `ui`)
- [ ] [CollapseFullScreenDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/CollapseFullScreenDialogFragment.java#L45)
- [ ] [FullScreenDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/FullScreenDialogFragment.java#L46)
- [ ] [TextInputDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/5b0d3f39c8cfe9c08b4e1547e46bc947f9be6b8f/WordPress/src/main/java/org/wordpress/android/ui/TextInputDialogFragment.java#L22)
- [x] [WPBottomSheetDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/WPBottomSheetDialogFragment.java#L4)

### Tasks (`WordPress` + `widgets`)
- [x] [AuthErrorDialogFragment.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/widgets/AuthErrorDialogFragment.java#L4)

### Tasks (`WordPress` + `inner static`)
- [ ] [PluginDetailActivity.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/plugins/PluginDetailActivity.java#L4) -> [DomainRegistrationPromptDialog](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/ui/plugins/PluginDetailActivity.java#L352-L374)
- [ ] [WPPrefView.java](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/widgets/WPPrefView.java#L4) -> [WPPrefDialogFragment](https://github.com/wordpress-mobile/WordPress-Android/blob/1b38e8c84f8e8b30626406fd0568beeffd8f7676/WordPress/src/main/java/org/wordpress/android/widgets/WPPrefView.java#L464-L512)