Thanks for your answer, but to tell the truth it is just a lot of empty words.
double-check your modifications (they do not magically change)
Use ManifestRequirementsOverride.xml (then why use AndroidManifest.xml?)
Placing the ManifestRequirementsOverride.xml in /Build/Android` directory sounds like a mistake, since many developers delete this directory and there by the modified manifest is gone. And will be overwritten in next build anyways.
Google Play Services Plugin (we are using whatever unreal has added in the plugin), so are you saying Unreal is giving us trash to work with?
Remove Permissions in Project Settings (he already told you he tried that, so why are you reposting to do it again)
Check the Build/Android/gradle.properties (again if we are on in the project this will get overwritten)