Flatpak: App Listing Quality improvements

[JavkhlanK]

Flathub recently added guidelines for app listing quality. Currently, the app is failing 5 checks:

Links of failing checks:

• Branding: Has primary brand colors
• App Name: Just the name
• Summary: Shorter than 35 characters
• Summary: Understandable for a non-technical person
• Summary: No weird formatting or punctuation
• This one seems off, but the link nonetheless: Screenshots: Default settings

I'm not too sure what to do in the brand colors case, but for the others I propose the following metainfo changes:

• maybe change the app name to "Galaxy Buds Manager" like in the app toolbar
• maybe change the summary to "Manage any Samsung Galaxy Buds device" (or remove Samsung if 35 characters is a hard guideline)
  • and since the first paragraph of the description is very similar to the summary, remove it

Also, since we're at it, the <developer_name> tag in the metainfo file should be replaced with a <developer> one, since the current one was deprecated. How about something like this:

<developer id="me.timschneeberger">
  <name>Tim Schneeberger</name>
</developer>

Lastly, just as a request, before a new release gets created, please add it to the metainfo file. That way it'd show up nicely in software update apps :)