[Mobile]Fix image upload progress not being displayed on the second time

[pinarol]

Description

To fix: wordpress-mobile/gutenberg-mobile#809

I had updated the upload listener to get started on componentDidMount and get removed at componentDidMount. Comparing to previous, new version will sometimes listen to upload events unnecessarily, but if I am not missing sth that's also the case when we have multiple image blocks uploading in parallel, we'll have some unrelated mediaUpload events coming in that case too. We trust the below check to ignore complications, it looked to me as we can lean on this and use a simpler logic for adding&removing listener for media upload events. Please correct me if I am missing sth because I might be :)

	mediaUpload( payload ) {
		const { attributes } = this.props;

		if ( payload.mediaId !== attributes.id ) {
			return;
		}

How has this been tested?

Tested with Parent PR: wordpress-mobile/gutenberg-mobile#811

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.

[mzorz]

Comparing to previous, new version will sometimes listen to upload events unnecessarily, but if I am not missing sth that's also the case when we have multiple image blocks uploading in parallel, we'll have some unrelated mediaUpload events coming in that case too. We trust the below check to ignore complications,

Sounds good to me! going to test shortly 👍

[mzorz]

Good catch @pinarol !
Tested, LGTM