Android: Fix sharing items from Joplin

[roman-r-m]

This is prompted by this bug report on the forum: https://discourse.joplinapp.org/t/android-lost-access-to-resources/15716/4

The issue here is a combination of 2 older bugs I've fixed before: #4557 & #4373 and a quirk in how Joplin handles deletion.

• Because of one of the above bugs, a resource ended up stored in Joplin with an empty title.

• When the user shared the resource, Joplin tried to copy the resource to give it the original name (taken from the title), but since the title was empty the copy failed.
  

  joplin/packages/app-mobile/components/NoteBodyViewer/hooks/useOnResourceLongPress.ts

  Lines 27 to 32 in ccbc329

  	const filename = resource.file_name ?
  	`${resource.file_name}.${resource.file_extension}` :
  	resource.title;
  	const targetPath = `${Setting.value('resourceDir')}/${filename}`;
  	await shim.fsDriver().copy(Resource.fullPath(resource), targetPath);

• For some reason RN copy implementation deletes the target in case of an error:
  

  joplin/packages/app-mobile/utils/fs-driver-rn.ts

  Lines 141 to 149 in 42c80e6

  	public async copy(source: string, dest: string) {
  	let retry = false;
  	try {
  	await RNFS.copyFile(source, dest);
  	} catch (error) {
  	// On iOS it will throw an error if the file already exist
  	retry = true;
  	await this.unlink(dest);
  	}

• In this case the target was the resource dir and this is how the user lost all his resources.

Changes in this PR:

• make sure the target name is never empty, if it is, use the default untitled
• instead of creating a copy in the same dir where all resources are stored, use the cache dir, presumably these files are less sensitive
• while fixing this I've noticed that when sharing to some apps (e.g. X-Plore File Manager) the call to Share.Open returns before the user has confirmed sharing, so Joplin deletes the file, and when the user finally confirms, the file is already gone. To fix this I've removed deletion. However according to Android docs the cache is not cleaned automatically so I've added a cleanup step on the app startup.
• Finally, I noticed that the new version of react-native-share has a bug (which I've introduced there myself), until it's fixed (in Android: fix sharing a single file react-native-share/react-native-share#984) I downgraded the version With it sharing works even though there's an exception in Android log

---

While there is no such bug on iOS, as far as I know, these changes use only the API available on both platforms, so I believe it should be compatible with iOS.

[roman-r-m]

* Finally, I noticed that the new version of `react-native-share` has a bug (which I've introduced there myself), until it's fixed (in [react-native-share/react-native-share#984](https://github.com/react-native-share/react-native-share/pull/984)) I downgraded the version With it sharing works even though there's an exception in Android log

This has been fixed in the latest version, I've updated the PR

[laurent22]

Thanks for the update @roman-r-m!

[PetrVladimirov]

@laurent22 - it is quite critical to have sharing functionality, especially while on travel... When to expect to have it rolled out to production? Thank you.